diff --git a/scripts/migrate-conversations.ts b/scripts/migrate-conversations.ts
new file mode 100644
index 0000000..151a7f1
--- /dev/null
+++ b/scripts/migrate-conversations.ts
@@ -0,0 +1,112 @@
+/**
+ * 기존 message_buffer 데이터를 새 conversation 테이블로 마이그레이션
+ *
+ * 사용법:
+ * 1. Worker 내부에서 1회성 호출
+ * 2. 또는 wrangler dev에서 수동 트리거
+ */
+
+import type { Env } from '../src/types';
+
+export async function migrateExistingConversations(env: Env): Promise<{
+  migrated_users: number;
+  migrated_messages: number;
+  errors: string[];
+}> {
+  const db = env.DB;
+  const result = {
+    migrated_users: 0,
+    migrated_messages: 0,
+    errors: [] as string[],
+  };
+
+  // 1. 기존 message_buffer에서 사용자 목록 조회
+  const { results: users } = await db
+    .prepare(`
+      SELECT DISTINCT u.telegram_id, mb.user_id
+      FROM message_buffer mb
+      JOIN users u ON mb.user_id = u.id
+    `)
+    .all<{ telegram_id: string; user_id: number }>();
+
+  if (!users || users.length === 0) {
+    console.log('마이그레이션 대상 없음');
+    return result;
+  }
+
+  console.log(`마이그레이션 대상 사용자: ${users.length}명`);
+
+  // 2. 각 사용자별 마이그레이션
+  for (const user of users) {
+    try {
+      const tableName = `conv_${user.telegram_id}`;
+
+      // 테이블 생성
+      await db.exec(`
+        CREATE TABLE IF NOT EXISTS ${tableName} (
+          id INTEGER PRIMARY KEY AUTOINCREMENT,
+          role TEXT NOT NULL CHECK(role IN ('user', 'assistant')),
+          content TEXT NOT NULL,
+          tool_calls TEXT,
+          tool_results TEXT,
+          created_at DATETIME DEFAULT CURRENT_TIMESTAMP
+        )
+      `);
+
+      await db.exec(`
+        CREATE INDEX IF NOT EXISTS idx_${tableName}_created ON ${tableName}(created_at DESC)
+      `);
+
+      // 메시지 복사
+      const { results: messages } = await db
+        .prepare(`
+          SELECT role, message as content, created_at
+          FROM message_buffer
+          WHERE user_id = ?
+          ORDER BY created_at ASC
+        `)
+        .bind(user.user_id)
+        .all<{ role: string; content: string; created_at: string }>();
+
+      if (messages && messages.length > 0) {
+        for (const msg of messages) {
+          // role 변환: bot -> assistant
+          const role = msg.role === 'bot' ? 'assistant' : 'user';
+          await db
+            .prepare(`INSERT INTO ${tableName} (role, content, created_at) VALUES (?, ?, ?)`)
+            .bind(role, msg.content, msg.created_at)
+            .run();
+        }
+
+        result.migrated_messages += messages.length;
+      }
+
+      // 메타 테이블에 등록 (이미 존재하면 업데이트)
+      await db
+        .prepare(`
+          INSERT INTO conversation_tables (telegram_id, table_name, message_count, last_message_at)
+          VALUES (?, ?, ?, (SELECT MAX(created_at) FROM ${tableName}))
+          ON CONFLICT(telegram_id) DO UPDATE SET
+            message_count = excluded.message_count,
+            last_message_at = excluded.last_message_at
+        `)
+        .bind(user.telegram_id, tableName, messages?.length || 0)
+        .run();
+
+      result.migrated_users++;
+      console.log(`✓ ${user.telegram_id}: ${messages?.length || 0}개 메시지 마이그레이션 완료`);
+
+    } catch (error) {
+      const errMsg = error instanceof Error ? error.message : String(error);
+      result.errors.push(`${user.telegram_id}: ${errMsg}`);
+      console.error(`✗ ${user.telegram_id}: 마이그레이션 실패 - ${errMsg}`);
+    }
+  }
+
+  console.log('\n=== 마이그레이션 결과 ===');
+  console.log(`사용자: ${result.migrated_users}명`);
+  console.log(`메시지: ${result.migrated_messages}개`);
+  console.log(`에러: ${result.errors.length}건`);
+
+  return result;
+}