diff --git a/PaddleCV/rcnn/eval_coco_map.py b/PaddleCV/rcnn/eval_coco_map.py
index 6baf30f0adc90c4f651cffb123862f3eb01cea2b..019bd877f244df5b3647cd3f227298b61842bf94 100644
--- a/PaddleCV/rcnn/eval_coco_map.py
+++ b/PaddleCV/rcnn/eval_coco_map.py
@@ -16,6 +16,7 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 import os
+import io
 import time
 import numpy as np
 from eval_helper import *
@@ -116,8 +117,8 @@ def eval():
             segms_res) > 0, "The number of valid mask detected is zero.\n \
             Please use reasonable model and check input data."
 
-    with open("detection_bbox_result.json", 'w') as outfile:
-        json.dump(dts_res, outfile)
+    with io.open("detection_bbox_result.json", 'w') as outfile:
+        outfile.write(unicode(json.dumps(dts_res)))
     print("start evaluate bbox using coco api")
     cocoDt = cocoGt.loadRes("detection_bbox_result.json")
     cocoEval = COCOeval(cocoGt, cocoDt, 'bbox')
@@ -126,8 +127,8 @@ def eval():
     cocoEval.summarize()
 
     if cfg.MASK_ON:
-        with open("detection_segms_result.json", 'w') as outfile:
-            json.dump(segms_res, outfile)
+        with io.open("detection_segms_result.json", 'w') as outfile:
+            outfile.write(unicode(json.dumps(segms_res)))
         print("start evaluate mask using coco api")
         cocoDt = cocoGt.loadRes("detection_segms_result.json")
         cocoEval = COCOeval(cocoGt, cocoDt, 'segm')
diff --git a/PaddleCV/ssd/data/pascalvoc/download.py b/PaddleCV/ssd/data/pascalvoc/download.py
index d4f8b7f33675013f8881ac8a69f28aa041c4023d..7e652c2936eb8705eb2ebba57bddddfa6ae53c58 100644
--- a/PaddleCV/ssd/data/pascalvoc/download.py
+++ b/PaddleCV/ssd/data/pascalvoc/download.py
@@ -15,6 +15,7 @@
 import os
 import os.path as osp
 import sys
+import io
 import re
 import random
 import tarfile
@@ -63,7 +64,7 @@ def walk_dir(devkit_dir, year):
             else:
                 continue
             fpath = osp.join(filelist_dir, fname)
-            for line in open(fpath):
+            for line in io.open(fpath):
                 name_prefix = line.strip().split()[0]
                 if name_prefix in added:
                     continue
@@ -85,11 +86,11 @@ def prepare_filelist(devkit_dir, years, output_dir):
         trainval_list.extend(trainval)
         test_list.extend(test)
     random.shuffle(trainval_list)
-    with open(osp.join(output_dir, 'trainval.txt'), 'w') as ftrainval:
+    with io.open(osp.join(output_dir, 'trainval.txt'), 'w') as ftrainval:
         for item in trainval_list:
             ftrainval.write(item[0] + ' ' + item[1] + '\n')
 
-    with open(osp.join(output_dir, 'test.txt'), 'w') as ftest:
+    with io.open(osp.join(output_dir, 'test.txt'), 'w') as ftest:
         for item in test_list:
             ftest.write(item[0] + ' ' + item[1] + '\n')
 
diff --git a/PaddleCV/ssd/eval_coco_map.py b/PaddleCV/ssd/eval_coco_map.py
index bccba40803293f38f6c8736f56b432e5244a1b16..e43391de49dd747aa488f73dd2255691622540cc 100644
--- a/PaddleCV/ssd/eval_coco_map.py
+++ b/PaddleCV/ssd/eval_coco_map.py
@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import os
+import io
 import time
 import numpy as np
 import argparse
@@ -128,8 +129,8 @@ def eval(args, data_args, test_list, batch_size, model_dir=None):
                 print("Batch {0}".format(batch_id))
             dts_res += get_dt_res(nmsed_out_v, data)
 
-        with open("detection_result.json", 'w') as outfile:
-            json.dump(dts_res, outfile)
+        with io.open("detection_result.json", 'w') as outfile:
+            outfile.write(unicode(json.dumps(dts_res)))
         print("start evaluate using coco api")
         cocoGt = COCO(os.path.join(data_args.data_dir, test_list))
         cocoDt = cocoGt.loadRes("detection_result.json")
diff --git a/PaddleCV/yolov3/eval.py b/PaddleCV/yolov3/eval.py
index 1d3e0844747d14e00a30f7d6a495feb8c86fa3ac..e2b2bc559ae5092109bf1cb26e3e48dac1cf2583 100644
--- a/PaddleCV/yolov3/eval.py
+++ b/PaddleCV/yolov3/eval.py
@@ -16,6 +16,7 @@ from __future__ import absolute_import
 from __future__ import division
 from __future__ import print_function
 import os
+import io
 import time
 import json
 import numpy as np
@@ -113,8 +114,8 @@ def eval():
         print("batch id: {}, time: {}".format(batch_id, end_time - start_time))
         total_time += end_time - start_time
 
-    with open("yolov3_result.json", 'w') as outfile:
-        json.dump(dts_res, outfile)
+    with io.open("yolov3_result.json", 'w') as outfile:
+        outfile.write(unicode(json.dumps(dts_res)))
     print("start evaluate detection result with coco api")
     coco = COCO(os.path.join(cfg.data_dir, test_list))
     cocoDt = coco.loadRes("yolov3_result.json")