diff --git a/src/di/generated/readerRouter.ts b/src/di/generated/readerRouter.ts
index f0b2a6c..d5d4815 100644
--- a/src/di/generated/readerRouter.ts
+++ b/src/di/generated/readerRouter.ts
@@ -145,6 +145,10 @@ export function getRouter(container: Container) {
     const controller = container.resolve(MarkController)
     return await controller.getMarkList(ctx, req)
   })
+  router.get('/v1/mark/users', async (req: Request, ctx: ContextManager) => {
+    const controller = container.resolve(MarkController)
+    return await controller.getMarkUsers(ctx, req)
+  })
   router.all('/v1/mcp/*', async (req: Request, ctx: ContextManager) => {
     const controller = container.resolve(McpServerController)
     return await controller.handleMcpRequest(ctx, req)
diff --git a/src/domain/mark.ts b/src/domain/mark.ts
index 9af7531..85d526a 100644
--- a/src/domain/mark.ts
+++ b/src/domain/mark.ts
@@ -409,4 +409,25 @@ export class MarkService {
 
     return res
   }
+
+  public async getMarkUsersByUserBookmarkUuid(ctx: ContextManager, userBookmarkUuid: string): Promise<{ uuid: string; nick_name: string; avatar: string }[]> {
+    const userBookmark = await this.bookmarkRepo.getUserBookmarkByUuid(userBookmarkUuid)
+    if (!userBookmark) throw BookmarkNotFoundError()
+
+    // check permission
+    if (userBookmark.user_id !== ctx.getUserId()) {
+      const share = await this.bookmarkRepo.getBookmarkShareByBookmarkId(userBookmark.bookmark_id, userBookmark.user_id)
+      if (!share || !share.is_enable) throw ShareActionNotAllowedError()
+    }
+
+    const userIds = await this.markRepo.getDistinctUserIdsByUserBookmarkUuid(userBookmarkUuid)
+    if (userIds.length === 0) return []
+
+    const users = await this.userRepo.getUserInfoList(userIds)
+    return users.map(u => ({
+      uuid: u.uuid,
+      nick_name: u.name,
+      avatar: u.picture
+    }))
+  }
 }
diff --git a/src/domain/orchestrator/sync.ts b/src/domain/orchestrator/sync.ts
index 5e85231..a1d0a97 100644
--- a/src/domain/orchestrator/sync.ts
+++ b/src/domain/orchestrator/sync.ts
@@ -1,4 +1,4 @@
-import { ErrorParam, SyncTableRuleError, SyncTableTagNameError, UserNotFoundError } from '../../const/err'
+import { ErrorMarkTypeError, ErrorParam, SyncTableRuleError, SyncTableTagNameError, UserNotFoundError } from '../../const/err'
 import { inject, injectable } from '../../decorators/di'
 import { ContextManager } from '../../utils/context'
 import { UserService } from '../user'
@@ -6,6 +6,7 @@ import { SignJWT } from 'jose'
 import { DBSyncBatchOperation } from '../../infra/repository/dbSyncBatch'
 import { QueueClient, queueRetryParseMessage, callbackType } from '../../infra/queue/queueClient'
 import { parserType, URLPolicie } from '../../utils/urlPolicie'
+import { markType } from '../../infra/repository/dbMark'
 
 export type SyncExecOperation = 'PUT' | 'PATCH' | 'DELETE'
 
@@ -52,6 +53,23 @@ export interface UpdateShareData {
   isEnable: boolean
 }
 
+export interface CreateCommentData {
+  userBookmarkUuid: string
+  type: number
+  source: string
+  comment: string
+  rootUuid: string
+  parentUuid: string
+  approxSource: string
+  content: string
+  sourceType: string
+  sourceId: string
+}
+
+export interface DeleteCommentData {
+  isDeleted: boolean
+}
+
 type SyncOperation<T extends string, D = undefined, U = string> = {
   userId: number
   type: T
@@ -66,6 +84,13 @@ type TagSyncOperation<T extends string, D = undefined, U = string> = {
   data: D
 }
 
+type CommentSyncOperation<T extends string, D = undefined, U = string> = {
+  userId: number
+  type: T
+  commentUuid: U
+  data: D
+}
+
 export type OrderedSyncOperation =
   | TagSyncOperation<'create_tag', CreateTagData, string>
   | SyncOperation<'create_bookmark', CreateBookmarkData, string>
@@ -73,6 +98,8 @@ export type OrderedSyncOperation =
   | SyncOperation<'update_tags', UpdateTagsData, string>
   | SyncOperation<'update_share', UpdateShareData, string>
   | SyncOperation<'delete_bookmark', undefined, string>
+  | CommentSyncOperation<'create_comment', CreateCommentData, string>
+  | CommentSyncOperation<'delete_comment', DeleteCommentData, string>
 
 export interface SyncChangeUserBookmark {
   uuid: string
@@ -140,6 +167,8 @@ export class SyncOrchestrator {
         this.processUserBookmarkChange(change, userId, orderedOperations)
       } else if (change.table === 'sr_user_tag' && change.op === 'PUT') {
         this.processUserTagChange(change, userId, orderedOperations)
+      } else if (change.table === 'sr_bookmark_comment') {
+        this.processUserBookmarkCommentChange(change, userId, orderedOperations)
       } else {
         throw SyncTableRuleError()
       }
@@ -151,6 +180,71 @@ export class SyncOrchestrator {
     }
   }
 
+  public processUserBookmarkCommentChange(change: SyncChangeItem, userId: number, operations: OrderedSyncOperation[]) {
+    if (!change.data) return
+
+    // soft delete comment
+    if (change.op === 'PATCH' && change.data && change.data.hasOwnProperty('is_deleted')) {
+      const isDeleted = change.data.is_deleted === 'true' || change.data.is_deleted === '1'
+      if (!isDeleted) return
+
+      operations.push({
+        type: 'delete_comment',
+        commentUuid: change.id,
+        userId,
+        data: {
+          isDeleted: true
+        }
+      })
+      return
+    }
+
+    // create comment
+    if (change.op === 'PUT') {
+      const userBookmarkUuid = change.data['user_bookmark_uuid'] || ''
+      if (!userBookmarkUuid) throw ErrorParam()
+
+      const type = parseInt(change.data['type'] || '0')
+      if (![markType.LINE, markType.COMMENT, markType.REPLY, markType.ORIGIN_LINE, markType.ORIGIN_COMMENT].includes(type)) {
+        throw ErrorMarkTypeError()
+      }
+
+      // 从 metadata 中提取 root_id、parent_id、source_id
+      let rootUuid = ''
+      let parentUuid = ''
+      let sourceId = ''
+      if (change.data['metadata']) {
+        try {
+          const metadata = JSON.parse(change.data['metadata']) as { root_id?: string; parent_id?: string; source_id?: string }
+          rootUuid = metadata.root_id || ''
+          parentUuid = metadata.parent_id || ''
+          sourceId = metadata.source_id || ''
+        } catch {
+          // metadata parse failure
+        }
+      }
+
+      operations.push({
+        type: 'create_comment',
+        commentUuid: change.id,
+        userId,
+        data: {
+          userBookmarkUuid,
+          type,
+          source: change.data['source'] || '[]',
+          comment: change.data['comment'] || '',
+          rootUuid,
+          parentUuid,
+          approxSource: change.data['approx_source'] || '',
+          content: change.data['content'] || '',
+          sourceType: sourceId ? 'bookmark' : '',
+          sourceId
+        }
+      })
+      return
+    }
+  }
+
   /** user bookmark change */
   public processUserBookmarkChange(change: SyncChangeItem, userId: number, operations: OrderedSyncOperation[]) {
     if (!change.data) return
diff --git a/src/handler/http/markController.ts b/src/handler/http/markController.ts
index 4afccdd..8ddf70c 100644
--- a/src/handler/http/markController.ts
+++ b/src/handler/http/markController.ts
@@ -72,4 +72,13 @@ export class MarkController {
     const listResult = await this.markService.getMarkList(ctx, page, size)
     return Successed(listResult)
   }
+
+  @Get('/users')
+  public async getMarkUsers(ctx: ContextManager, request: Request) {
+    const req = await RequestUtils.query<{ user_bookmark_uuid: string }>(request)
+    if (!req || !req.user_bookmark_uuid) return Failed(ErrorParam())
+
+    const users = await this.markService.getMarkUsersByUserBookmarkUuid(ctx, req.user_bookmark_uuid)
+    return Successed(users)
+  }
 }
diff --git a/src/infra/repository/dbBookmark.ts b/src/infra/repository/dbBookmark.ts
index d2401de..1fe64ad 100644
--- a/src/infra/repository/dbBookmark.ts
+++ b/src/infra/repository/dbBookmark.ts
@@ -214,6 +214,10 @@ export class BookmarkRepo {
     return await this.prismaPg().sr_user_bookmark.findFirst({ where: { uuid: uid, user_id: userId }, include: { bookmark: true } })
   }
 
+  public async getUserBookmarkByUuid(uuid: string) {
+    return await this.prismaPg().sr_user_bookmark.findFirst({ where: { uuid } })
+  }
+
   public async getUserBookmarkByUserBmId(userBmId: number) {
     return await this.prismaPg().sr_user_bookmark.findFirst({ where: { id: userBmId }, include: { bookmark: true } })
   }
diff --git a/src/infra/repository/dbMark.ts b/src/infra/repository/dbMark.ts
index 81ca83e..692b554 100644
--- a/src/infra/repository/dbMark.ts
+++ b/src/infra/repository/dbMark.ts
@@ -193,4 +193,13 @@ export class MarkRepo {
       take: size
     })
   }
+
+  async getDistinctUserIdsByUserBookmarkUuid(userBookmarkUuid: string): Promise<number[]> {
+    const comments = await this.prismaPg().sr_bookmark_comment.findMany({
+      where: { user_bookmark_uuid: userBookmarkUuid, is_deleted: false },
+      select: { user_id: true },
+      distinct: ['user_id']
+    })
+    return comments.map(c => c.user_id)
+  }
 }
diff --git a/src/infra/repository/dbSyncBatch.ts b/src/infra/repository/dbSyncBatch.ts
index af6491e..7d7c550 100644
--- a/src/infra/repository/dbSyncBatch.ts
+++ b/src/infra/repository/dbSyncBatch.ts
@@ -2,7 +2,18 @@ import { PRISIMA_HYPERDRIVE_CLIENT } from '../../const/symbol'
 import { inject, injectable } from '../../decorators/di'
 import { LazyInstance } from '../../decorators/lazy'
 import { Prisma, PrismaClient as HyperdrivePrismaClient } from '@prisma/hyperdrive-client'
-import { OrderedSyncOperation, CreateTagData, CreateBookmarkData, UpdateBookmarkData, UpdateTagsData, UpdateShareData } from '../../domain/orchestrator/sync'
+import {
+  OrderedSyncOperation,
+  CreateTagData,
+  CreateBookmarkData,
+  UpdateBookmarkData,
+  UpdateTagsData,
+  UpdateShareData,
+  CreateCommentData,
+  DeleteCommentData
+} from '../../domain/orchestrator/sync'
+import { CommentTooLongError, ErrorMarkTypeError, MarkLineTooLongError, ShareActionNotAllowedError } from '../../const/err'
+import { markType } from './dbMark'
 
 export type prismaTx = Omit<HyperdrivePrismaClient<Prisma.PrismaClientOptions>, '$connect' | '$disconnect' | '$on' | '$transaction' | '$extends'>
 export type executeFunction = (tx: prismaTx, operation: OrderedSyncOperation) => Promise<{ bookmarkId: number; targetUrl: string; userId: number } | null | void>
@@ -22,7 +33,9 @@ export class DBSyncBatchOperation {
       update_bookmark: this.executeUpdateBookmark,
       update_tags: this.executeUpdateTags,
       update_share: this.executeUpdateShare,
-      delete_bookmark: this.executeDeleteBookmark
+      delete_bookmark: this.executeDeleteBookmark,
+      create_comment: this.executeCreateComment,
+      delete_comment: this.executeDeleteComment
     }
 
     await this.prismaHyperdrive().$transaction(async tx => {
@@ -219,4 +232,121 @@ export class DBSyncBatchOperation {
       data: { deleted_at: new Date() }
     })
   }
+
+  /** create comment */
+  public async executeCreateComment(tx: prismaTx, operation: OrderedSyncOperation): Promise<void> {
+    if (operation.type !== 'create_comment') return
+
+    const { userBookmarkUuid, type, source, comment, rootUuid, parentUuid, approxSource, content, sourceType, sourceId } = operation.data as CreateCommentData
+
+    if (type === markType.LINE && comment) throw ErrorMarkTypeError()
+    if (type === markType.COMMENT && (!comment || comment.length < 1)) throw ErrorMarkTypeError()
+    if (type === markType.REPLY && (!comment || comment.length < 1)) throw ErrorMarkTypeError()
+    if ([markType.ORIGIN_COMMENT, markType.ORIGIN_LINE].includes(type) && !approxSource) throw ErrorMarkTypeError()
+    if (comment && comment.length > 1500) throw CommentTooLongError()
+
+    // 校验 source 长度（非回复类型）
+    if (type !== markType.REPLY) {
+      try {
+        const sourceItems = JSON.parse(source) as Array<{ type: string; start: number; end: number }>
+        if (Array.isArray(sourceItems)) {
+          let sourceLength = 0
+          let sourceImageCount = 0
+          sourceItems.forEach(item => {
+            if (item.type === 'image') sourceImageCount++
+            else sourceLength += (item.end || 0) - (item.start || 0)
+          })
+          if (sourceLength > 1000 || sourceImageCount > 3) throw MarkLineTooLongError()
+        }
+      } catch (e) {
+        if (e instanceof Error && (e.message.includes('MarkLine') || e.message.includes('MARK_LINE'))) throw e
+      }
+    }
+
+    // 查找目标书签（sr_user_bookmark）
+    const userBookmark = await tx.sr_user_bookmark.findUnique({
+      where: { uuid: userBookmarkUuid }
+    })
+    if (!userBookmark) throw ShareActionNotAllowedError()
+
+    // 权限校验：本人书签直接放行，非本人需检查是否开启分享
+    if (userBookmark.user_id !== operation.userId) {
+      const share = await tx.sr_bookmark_share.findFirst({
+        where: { bookmark_id: userBookmark.bookmark_id, user_id: userBookmark.user_id, is_enable: true }
+      })
+      if (!share) throw ShareActionNotAllowedError()
+    }
+
+    // 通过 UUID 解析 root_id 和 parent_id 对应的整数 ID
+    let rootId = 0
+    let parentId = 0
+
+    if (rootUuid) {
+      const rootComment = await tx.sr_bookmark_comment.findUnique({ where: { uuid: rootUuid } })
+      if (rootComment) rootId = rootComment.id
+    }
+
+    if (type === markType.REPLY && parentUuid) {
+      const parentComment = await tx.sr_bookmark_comment.findUnique({ where: { uuid: parentUuid } })
+      if (!parentComment) throw ShareActionNotAllowedError()
+      if (parentComment.bookmark_id !== userBookmark.id) throw ShareActionNotAllowedError()
+      if (parentComment.is_deleted) throw ShareActionNotAllowedError()
+      parentId = parentComment.id
+      if (parentComment.root_id > 0) rootId = parentComment.root_id
+    }
+
+    const created = await tx.sr_bookmark_comment.create({
+      data: {
+        uuid: operation.commentUuid,
+        user_id: operation.userId,
+        bookmark_id: userBookmark.id,
+        user_bookmark_uuid: userBookmarkUuid,
+        type,
+        source,
+        comment,
+        root_id: rootId,
+        parent_id: parentId,
+        approx_source: approxSource,
+        content,
+        source_type: sourceType,
+        source_id: sourceId,
+        is_deleted: false,
+        created_at: new Date(),
+        updated_at: new Date()
+      }
+    })
+
+    if ([markType.COMMENT, markType.ORIGIN_COMMENT].includes(type) && rootId === 0) {
+      await tx.sr_bookmark_comment.update({
+        where: { id: created.id },
+        data: { root_id: created.id, updated_at: new Date() }
+      })
+    }
+  }
+
+  /** soft delete comment */
+  public async executeDeleteComment(tx: prismaTx, operation: OrderedSyncOperation): Promise<void> {
+    if (operation.type !== 'delete_comment') return
+
+    const { isDeleted } = operation.data as DeleteCommentData
+
+    const commentRecord = await tx.sr_bookmark_comment.findUnique({
+      where: { uuid: operation.commentUuid }
+    })
+    if (!commentRecord) return
+
+    // 权限校验：评论作者可删除自己的评论，书签拥有者可删除其书签下的任意评论
+    if (commentRecord.user_id !== operation.userId) {
+      // bookmark_id 存的是 sr_user_bookmark.id，用 id 去查
+      const userBookmark = await tx.sr_user_bookmark.findFirst({
+        where: { id: commentRecord.bookmark_id, user_id: operation.userId }
+      })
+      if (!userBookmark) throw ShareActionNotAllowedError()
+    }
+
+    await tx.sr_bookmark_comment.update({
+      where: { uuid: operation.commentUuid },
+      data: { is_deleted: isDeleted, updated_at: new Date() }
+    })
+  }
 }