diff --git a/python/examples/imagenet/benchmark.py b/python/examples/imagenet/benchmark.py
index 0181b873a36c0e65beff1d03f750b5d78c89aa06..8bbb88759edcf0ddc34dba32baf7fec538165e28 100644
--- a/python/examples/imagenet/benchmark.py
+++ b/python/examples/imagenet/benchmark.py
@@ -90,6 +90,7 @@ def single_func(idx, resource):
                 image = base64.b64encode(
                     open("./image_data/n01440764/" + file_list[i]).read())
             else:
+                image_path = "./image_data/n01440764/" + file_list[i]
                 image = base64.b64encode(open(image_path, "rb").read()).decode(
                     "utf-8")
             req = json.dumps({"feed": [{"image": image}], "fetch": ["score"]})
@@ -106,7 +107,7 @@ if __name__ == '__main__':
     endpoint_list = [
         "127.0.0.1:9292", "127.0.0.1:9293", "127.0.0.1:9294", "127.0.0.1:9295"
     ]
-    turns = 100
+    turns = 1
     start = time.time()
     result = multi_thread_runner.run(
         single_func, args.thread, {"endpoint": endpoint_list,
diff --git a/python/examples/imagenet/resnet50_web_service.py b/python/examples/imagenet/resnet50_web_service.py
index e7d1914973f2aeb58a912f7d85e35f85718d7a9b..a3f4709cc5a999704ccd9a4e52165d32498bc340 100644
--- a/python/examples/imagenet/resnet50_web_service.py
+++ b/python/examples/imagenet/resnet50_web_service.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 import sys
 from paddle_serving_client import Client
-from paddle_serving_app.reader import Sequential, URL2Image, Resize, CenterCrop, RGB2BGR, Transpose, Div, Normalize
+from paddle_serving_app.reader import Sequential, URL2Image, Resize, CenterCrop, RGB2BGR, Transpose, Div, Normalize, Base64ToImage
 
 if len(sys.argv) != 4:
     print("python resnet50_web_service.py model device port")
@@ -30,7 +30,7 @@ else:
 class ImageService(WebService):
     def init_imagenet_setting(self):
         self.seq = Sequential([
-            URL2Image(), Resize(256), CenterCrop(224), RGB2BGR(), Transpose(
+            Base64ToImage(), Resize(256), CenterCrop(224), RGB2BGR(), Transpose(
                 (2, 0, 1)), Div(255), Normalize([0.485, 0.456, 0.406],
                                                 [0.229, 0.224, 0.225], True)
         ])
diff --git a/python/paddle_serving_app/reader/__init__.py b/python/paddle_serving_app/reader/__init__.py
index 93e2cd76102d93f52955060055afda34f9576ed8..e9fd3154cda1873a4907e7372b8ab561f7cd1d66 100644
--- a/python/paddle_serving_app/reader/__init__.py
+++ b/python/paddle_serving_app/reader/__init__.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 from .chinese_bert_reader import ChineseBertReader
-from .image_reader import ImageReader, File2Image, URL2Image, Sequential, Normalize
+from .image_reader import ImageReader, File2Image, URL2Image, Sequential, Normalize, Base64ToImage
 from .image_reader import CenterCrop, Resize, Transpose, Div, RGB2BGR, BGR2RGB, ResizeByFactor
 from .image_reader import RCNNPostprocess, SegPostprocess, PadStride
 from .image_reader import DBPostProcess, FilterBoxes, GetRotateCropImage, SortedBoxes
diff --git a/python/paddle_serving_server/web_service.py b/python/paddle_serving_server/web_service.py
index 78f574871c4e198e7dd7383db9e96e82a5c0bfe3..9430da83ef1b3add9b79d305f03d2aef195028a6 100644
--- a/python/paddle_serving_server/web_service.py
+++ b/python/paddle_serving_server/web_service.py
@@ -123,7 +123,7 @@ class WebService(object):
                 feed=request.json["feed"], fetch=fetch, fetch_map=fetch_map)
             result = {"result": result}
         except ValueError as err:
-            result = {"result": err}
+            result = {"result": str(err)}
         return result
 
     def run_rpc_service(self):
diff --git a/python/paddle_serving_server_gpu/web_service.py b/python/paddle_serving_server_gpu/web_service.py
index 4154e8242b7c26847c171bf9c71a7923687348fa..ea72f1869f1c0b84a088221a9770366e7432879d 100644
--- a/python/paddle_serving_server_gpu/web_service.py
+++ b/python/paddle_serving_server_gpu/web_service.py
@@ -178,7 +178,7 @@ class WebService(object):
                 feed=request.json["feed"], fetch=fetch, fetch_map=fetch_map)
             result = {"result": result}
         except ValueError as err:
-            result = {"result": err}
+            result = {"result": str(err)}
         return result
 
     def run_rpc_service(self):