diff --git a/packages/adapters/postgres/__init__.py b/packages/adapters/postgres/__init__.py
new file mode 100644
index 000000000..598c1f8dd
--- /dev/null
+++ b/packages/adapters/postgres/__init__.py
@@ -0,0 +1,12 @@
+"""
+PostgreSQL 适配器
+"""
+from packages.adapters.postgres.user_repository import PostgresUserRepository
+from packages.adapters.postgres.workspace_repository import PostgresWorkspaceRepository
+from packages.adapters.postgres.workspace_member_repository import PostgresWorkspaceMemberRepository
+
+__all__ = [
+    "PostgresUserRepository",
+    "PostgresWorkspaceRepository",
+    "PostgresWorkspaceMemberRepository",
+]
diff --git a/packages/adapters/postgres/workspace_member_repository.py b/packages/adapters/postgres/workspace_member_repository.py
new file mode 100644
index 000000000..d4d696436
--- /dev/null
+++ b/packages/adapters/postgres/workspace_member_repository.py
@@ -0,0 +1,138 @@
+"""
+PostgreSQL WorkspaceMember Repository 实现
+"""
+from typing import Optional, List
+import psycopg2
+from psycopg2.extras import RealDictCursor
+
+from packages.domain.entities import WorkspaceMember
+from packages.ports.workspace_member_repository import WorkspaceMemberRepository
+
+
+class PostgresWorkspaceMemberRepository(WorkspaceMemberRepository):
+    """WorkspaceMember 仓储 PostgreSQL 实现"""
+    
+    def __init__(self, connection_string: str):
+        self.connection_string = connection_string
+    
+    def _get_connection(self):
+        return psycopg2.connect(self.connection_string, cursor_factory=RealDictCursor)
+    
+    def save(self, member: WorkspaceMember) -> None:
+        """保存成员"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute("""
+                    INSERT INTO workspace_members (
+                        id, workspace_id, user_id, role, invited_by, joined_at
+                    ) VALUES (
+                        %(id)s, %(workspace_id)s, %(user_id)s, %(role)s,
+                        %(invited_by)s, %(joined_at)s
+                    )
+                    ON CONFLICT (workspace_id, user_id) DO UPDATE SET
+                        role = EXCLUDED.role
+                """, {
+                    "id": member.id,
+                    "workspace_id": member.workspace_id,
+                    "user_id": member.user_id,
+                    "role": member.role,
+                    "invited_by": member.invited_by,
+                    "joined_at": member.joined_at,
+                })
+            conn.commit()
+        finally:
+            conn.close()
+    
+    def find_by_id(self, member_id: str) -> Optional[WorkspaceMember]:
+        """根据 ID 查找成员"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute("SELECT * FROM workspace_members WHERE id = %s", (member_id,))
+                row = cur.fetchone()
+                return self._row_to_member(row) if row else None
+        finally:
+            conn.close()
+    
+    def find_by_workspace_and_user(
+        self,
+        workspace_id: str,
+        user_id: str,
+    ) -> Optional[WorkspaceMember]:
+        """根据 workspace 和 user 查找成员"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT * FROM workspace_members WHERE workspace_id = %s AND user_id = %s",
+                    (workspace_id, user_id)
+                )
+                row = cur.fetchone()
+                return self._row_to_member(row) if row else None
+        finally:
+            conn.close()
+    
+    def find_by_user(self, user_id: str) -> List[WorkspaceMember]:
+        """查找用户的所有成员记录"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT * FROM workspace_members WHERE user_id = %s ORDER BY joined_at DESC",
+                    (user_id,)
+                )
+                rows = cur.fetchall()
+                return [self._row_to_member(row) for row in rows]
+        finally:
+            conn.close()
+    
+    def find_by_workspace(self, workspace_id: str) -> List[WorkspaceMember]:
+        """查找 workspace 的所有成员"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT * FROM workspace_members WHERE workspace_id = %s ORDER BY joined_at",
+                    (workspace_id,)
+                )
+                rows = cur.fetchall()
+                return [self._row_to_member(row) for row in rows]
+        finally:
+            conn.close()
+    
+    def count_by_workspace(self, workspace_id: str) -> int:
+        """统计 workspace 的成员数量"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute(
+                    "SELECT COUNT(*) FROM workspace_members WHERE workspace_id = %s",
+                    (workspace_id,)
+                )
+                return cur.fetchone()["count"]
+        finally:
+            conn.close()
+    
+    def delete(self, member_id: str) -> bool:
+        """删除成员"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute("DELETE FROM workspace_members WHERE id = %s", (member_id,))
+                deleted = cur.rowcount > 0
+            conn.commit()
+            return deleted
+        finally:
+            conn.close()
+    
+    def _row_to_member(self, row: dict) -> WorkspaceMember:
+        """将数据库行转换为 WorkspaceMember 对象"""
+        return WorkspaceMember(
+            id=row["id"],
+            workspace_id=row["workspace_id"],
+            user_id=row["user_id"],
+            role=row["role"],
+            invited_by=row["invited_by"],
+            joined_at=row["joined_at"],
+        )
diff --git a/packages/adapters/postgres/workspace_repository.py b/packages/adapters/postgres/workspace_repository.py
new file mode 100644
index 000000000..967793d5c
--- /dev/null
+++ b/packages/adapters/postgres/workspace_repository.py
@@ -0,0 +1,100 @@
+"""
+PostgreSQL Workspace Repository 实现
+"""
+from typing import Optional
+import psycopg2
+from psycopg2.extras import RealDictCursor
+
+from packages.domain.entities import Workspace
+from packages.ports.workspace_repository import WorkspaceRepository
+
+
+class PostgresWorkspaceRepository(WorkspaceRepository):
+    """Workspace 仓储 PostgreSQL 实现"""
+    
+    def __init__(self, connection_string: str):
+        self.connection_string = connection_string
+    
+    def _get_connection(self):
+        """获取数据库连接"""
+        return psycopg2.connect(self.connection_string, cursor_factory=RealDictCursor)
+    
+    def save(self, workspace: Workspace) -> None:
+        """保存工作空间"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute("""
+                    INSERT INTO workspaces (
+                        id, name, owner_user_id, subscription_plan,
+                        subscription_status, subscription_expires_at,
+                        max_projects, max_storage_gb, used_storage_gb, created_at
+                    ) VALUES (
+                        %(id)s, %(name)s, %(owner_user_id)s, %(subscription_plan)s,
+                        %(subscription_status)s, %(subscription_expires_at)s,
+                        %(max_projects)s, %(max_storage_gb)s, %(used_storage_gb)s, %(created_at)s
+                    )
+                    ON CONFLICT (id) DO UPDATE SET
+                        name = EXCLUDED.name,
+                        subscription_plan = EXCLUDED.subscription_plan,
+                        subscription_status = EXCLUDED.subscription_status,
+                        subscription_expires_at = EXCLUDED.subscription_expires_at,
+                        max_projects = EXCLUDED.max_projects,
+                        max_storage_gb = EXCLUDED.max_storage_gb,
+                        used_storage_gb = EXCLUDED.used_storage_gb
+                """, {
+                    "id": workspace.id,
+                    "name": workspace.name,
+                    "owner_user_id": workspace.owner_user_id,
+                    "subscription_plan": workspace.subscription_plan,
+                    "subscription_status": workspace.subscription_status,
+                    "subscription_expires_at": workspace.subscription_expires_at,
+                    "max_projects": workspace.max_projects,
+                    "max_storage_gb": workspace.max_storage_gb,
+                    "used_storage_gb": workspace.used_storage_gb,
+                    "created_at": workspace.created_at,
+                })
+            conn.commit()
+        finally:
+            conn.close()
+    
+    def find_by_id(self, workspace_id: str) -> Optional[Workspace]:
+        """根据 ID 查找工作空间"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute("SELECT * FROM workspaces WHERE id = %s", (workspace_id,))
+                row = cur.fetchone()
+                
+                if row:
+                    return self._row_to_workspace(row)
+                return None
+        finally:
+            conn.close()
+    
+    def delete(self, workspace_id: str) -> bool:
+        """删除工作空间"""
+        conn = self._get_connection()
+        try:
+            with conn.cursor() as cur:
+                cur.execute("DELETE FROM workspaces WHERE id = %s", (workspace_id,))
+                deleted = cur.rowcount > 0
+            conn.commit()
+            return deleted
+        finally:
+            conn.close()
+    
+    def _row_to_workspace(self, row: dict) -> Workspace:
+        """将数据库行转换为 Workspace 对象"""
+        return Workspace(
+            id=row["id"],
+            name=row["name"],
+            owner_user_id=row["owner_user_id"],
+            subscription_plan=row["subscription_plan"],
+            subscription_status=row["subscription_status"],
+            subscription_expires_at=row["subscription_expires_at"],
+            max_projects=row["max_projects"],
+            max_storage_gb=row["max_storage_gb"],
+            used_storage_gb=float(row["used_storage_gb"]),
+            created_at=row["created_at"],
+        )