diff --git a/openviking/storage/viking_fs.py b/openviking/storage/viking_fs.py
index 37ceec16..7821ce68 100644
--- a/openviking/storage/viking_fs.py
+++ b/openviking/storage/viking_fs.py
@@ -150,7 +150,8 @@ async def mkdir(self, uri: str, mode: str = "755", exist_ok: bool = False) -> No
                 return None
             except Exception:
                 pass
-        return
+
+        await asyncio.to_thread(self.agfs.mkdir, path)
 
     async def rm(self, uri: str, recursive: bool = False) -> Dict[str, Any]:
         """Delete file/directory + recursively update vector index."""
diff --git a/tests/README.md b/tests/README.md
index d2fb0c9e..cd4d03c6 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -157,6 +157,7 @@ Miscellaneous tests.
 | `test_config_validation.py` | Configuration validation | Config schema validation, required fields, type checking |
 | `test_debug_service.py` | Debug service | Debug endpoint tests, service diagnostics |
 | `test_extract_zip.py` | Zip extraction security (Zip Slip) | Path traversal prevention (`../`), absolute path rejection, symlink entry filtering, backslash traversal, UNC path rejection, directory entry skipping, normal extraction |
+| `test_mkdir.py` | VikingFS.mkdir() fix verification | mkdir calls agfs.mkdir, exist_ok=True skips existing, exist_ok=True creates missing, default creation, parent-before-target ordering |
 | `test_port_check.py` | AGFS port check socket leak fix | Available port no leak, occupied port raises RuntimeError, occupied port no ResourceWarning |
 
 ### engine/
diff --git a/tests/misc/test_mkdir.py b/tests/misc/test_mkdir.py
new file mode 100644
index 00000000..5c559971
--- /dev/null
+++ b/tests/misc/test_mkdir.py
@@ -0,0 +1,89 @@
+#!/usr/bin/env python3
+# Copyright (c) 2026 Beijing Volcano Engine Technology Co., Ltd.
+# SPDX-License-Identifier: Apache-2.0
+"""Tests for VikingFS.mkdir() — verifies the target directory is actually created."""
+
+import os
+import sys
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))))
+
+
+def _make_viking_fs():
+    """Create a VikingFS instance with mocked AGFS backend."""
+    from openviking.storage.viking_fs import VikingFS
+
+    fs = VikingFS.__new__(VikingFS)
+    fs.agfs = MagicMock()
+    fs.agfs.mkdir = MagicMock(return_value=None)
+    fs.query_embedder = None
+    fs.vector_store = None
+    fs._uri_prefix = "viking://"
+    return fs
+
+
+class TestMkdir:
+    """Test that mkdir() actually creates the target directory."""
+
+    @pytest.mark.asyncio
+    async def test_mkdir_calls_agfs_mkdir(self):
+        """mkdir() must call agfs.mkdir with the target path."""
+        fs = _make_viking_fs()
+        fs._ensure_parent_dirs = AsyncMock()
+        fs.stat = AsyncMock(side_effect=Exception("not found"))
+
+        await fs.mkdir("viking://resources/new_dir")
+
+        fs.agfs.mkdir.assert_called_once()
+        call_path = fs.agfs.mkdir.call_args[0][0]
+        assert call_path.endswith("resources/new_dir")
+
+    @pytest.mark.asyncio
+    async def test_mkdir_exist_ok_true_existing(self):
+        """mkdir(exist_ok=True) should return early if directory exists."""
+        fs = _make_viking_fs()
+        fs._ensure_parent_dirs = AsyncMock()
+        fs.stat = AsyncMock(return_value={"type": "directory"})
+
+        await fs.mkdir("viking://resources/existing_dir", exist_ok=True)
+
+        # Should NOT call agfs.mkdir because directory already exists
+        fs.agfs.mkdir.assert_not_called()
+
+    @pytest.mark.asyncio
+    async def test_mkdir_exist_ok_true_not_existing(self):
+        """mkdir(exist_ok=True) should create dir if it does not exist."""
+        fs = _make_viking_fs()
+        fs._ensure_parent_dirs = AsyncMock()
+        fs.stat = AsyncMock(side_effect=Exception("not found"))
+
+        await fs.mkdir("viking://resources/new_dir", exist_ok=True)
+
+        fs.agfs.mkdir.assert_called_once()
+        call_path = fs.agfs.mkdir.call_args[0][0]
+        assert call_path.endswith("resources/new_dir")
+
+    @pytest.mark.asyncio
+    async def test_mkdir_exist_ok_false_default(self):
+        """mkdir(exist_ok=False) should always attempt to create."""
+        fs = _make_viking_fs()
+        fs._ensure_parent_dirs = AsyncMock()
+
+        await fs.mkdir("viking://resources/another_dir")
+
+        fs.agfs.mkdir.assert_called_once()
+
+    @pytest.mark.asyncio
+    async def test_mkdir_ensures_parents_first(self):
+        """mkdir() must call _ensure_parent_dirs before creating target."""
+        fs = _make_viking_fs()
+        call_order = []
+        fs._ensure_parent_dirs = AsyncMock(side_effect=lambda p: call_order.append("parents"))
+        fs.agfs.mkdir = MagicMock(side_effect=lambda p: call_order.append("mkdir"))
+
+        await fs.mkdir("viking://a/b/c")
+
+        assert call_order == ["parents", "mkdir"]