diff --git a/src/domain/orchestrator/sync.ts b/src/domain/orchestrator/sync.ts
index a1d0a97..c66f7d2 100644
--- a/src/domain/orchestrator/sync.ts
+++ b/src/domain/orchestrator/sync.ts
@@ -209,16 +209,13 @@ export class SyncOrchestrator {
         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 }
+          const metadata = JSON.parse(change.data['metadata']) as { root_id?: string; parent_id?: string }
           rootUuid = metadata.root_id || ''
           parentUuid = metadata.parent_id || ''
-          sourceId = metadata.source_id || ''
         } catch {
           // metadata parse failure
         }
@@ -237,8 +234,8 @@ export class SyncOrchestrator {
           parentUuid,
           approxSource: change.data['approx_source'] || '',
           content: change.data['content'] || '',
-          sourceType: sourceId ? 'bookmark' : '',
-          sourceId
+          sourceType: 'bookmark',
+          sourceId: ''
         }
       })
       return
diff --git a/src/infra/repository/dbSyncBatch.ts b/src/infra/repository/dbSyncBatch.ts
index 7d7c550..8a1a6ef 100644
--- a/src/infra/repository/dbSyncBatch.ts
+++ b/src/infra/repository/dbSyncBatch.ts
@@ -295,6 +295,9 @@ export class DBSyncBatchOperation {
       if (parentComment.root_id > 0) rootId = parentComment.root_id
     }
 
+    const finalSourceType = sourceType || 'bookmark'
+    const finalSourceId = sourceId || userBookmark.id.toString()
+
     const created = await tx.sr_bookmark_comment.create({
       data: {
         uuid: operation.commentUuid,
@@ -308,8 +311,8 @@ export class DBSyncBatchOperation {
         parent_id: parentId,
         approx_source: approxSource,
         content,
-        source_type: sourceType,
-        source_id: sourceId,
+        source_type: finalSourceType,
+        source_id: finalSourceId,
         is_deleted: false,
         created_at: new Date(),
         updated_at: new Date()