diff --git a/yolov3/README.md b/yolov3/README.md
index e899daaf4b655a02e1ee5404375bd9c5b93b139b..7165206387b7271f33341fbf3fd472ea699b1e28 100644
--- a/yolov3/README.md
+++ b/yolov3/README.md
@@ -75,29 +75,27 @@ YOLOv3 的网络结构由基础特征提取网络、multi-scale特征融合层
 
 ### 数据准备
 
-在[MS-COCO数据集](http://cocodataset.org/#download)上进行训练，通过如下方式下载数据集。
+模型目前支持COCO数据集格式的数据读入和精度评估，我们同时提供了将转换为COCO数据集的格式的Pascal VOC数据集下载，可通过如下命令下载。
 
   ```bash
-  python dataset/coco/download.py
+  python dataset/voc/download.py
   ```
 
 数据目录结构如下：
 
   ```
-  dataset/coco/
+  dataset/voc/
   ├── annotations
-  │   ├── instances_train2014.json
   │   ├── instances_train2017.json
-  │   ├── instances_val2014.json
   │   ├── instances_val2017.json
   |   ...
   ├── train2017
-  │   ├── 000000000009.jpg
-  │   ├── 000000580008.jpg
+  │   ├── 1013.jpg
+  │   ├── 1014.jpg
   |   ...
   ├── val2017
-  │   ├── 000000000139.jpg
-  │   ├── 000000000285.jpg
+  │   ├── 2551.jpg
+  │   ├── 2552.jpg
   |   ...
   ```
 
@@ -140,15 +138,17 @@ YOLOv3模型输出为LoDTensor，只支持使用batch_size为1进行评估，可
 1. 自动下载Paddle发布的[YOLOv3-DarkNet53](https://paddlemodels.bj.bcebos.com/hapi/yolov3_darknet53.pdparams)权重评估
 
 ```bash
-python main.py --data=<path/to/dataset> --eval_only
+python main.py --data=dataset/voc  --eval_only
 ```
 
 2. 加载checkpoint进行精度评估
 
 ```bash
-python main.py --data=<path/to/dataset> --eval_only --weights=yolo_checkpoint/final
+python main.py --data=dataset/voc --eval_only --weights=yolo_checkpoint/no_mixup/final
 ```
 
+同样可以通过指定`-d`参数进行动态图模式的评估。
+
 #### 评估精度
 
 在10类小数据集下训练模型权重见[YOLOv3-DarkNet53](https://paddlemodels.bj.bcebos.com/hapi/yolov3_darknet53.pdparams)，评估精度如下：
@@ -168,6 +168,33 @@ Average Recall     (AR) @[ IoU=0.50:0.95 | area=medium | maxDets=100 ] = 0.506
 Average Recall     (AR) @[ IoU=0.50:0.95 | area= large | maxDets=100 ] = 0.670
 ```
 
+### 模型推断及可视化
+
+可通过如下两种方式进行模型推断。
+
+1. 自动下载Paddle发布的[YOLOv3-DarkNet53](https://paddlemodels.bj.bcebos.com/hapi/yolov3_darknet53.pdparams)权重评估
+
+```bash
+python infer.py --label_list=dataset/voc/label_list.txt --infer_image=image/dog.jpg
+```
+
+2. 加载checkpoint进行精度评估
+
+```bash
+python infer.py --label_list=dataset/voc/label_list.txt --infer_image=image/dog.jpg --weights=yolo_checkpoint/mo_mixup/final
+```
+
+推断结果可视化图像会保存于`--output`指定的文件夹下，默认保存于`./output`目录。
+
+模型推断会输出如下检测结果日志：
+
+```text
+2020-04-02 08:26:47,268-INFO: detect bicycle at [116.14993, 127.278336, 579.7716, 438.44214] score: 0.97
+2020-04-02 08:26:47,273-INFO: detect dog at [127.44086, 215.71997, 316.04276, 539.7584] score: 0.99
+2020-04-02 08:26:47,274-INFO: detect car at [475.42343, 80.007484, 687.16095, 171.27374] score: 0.98
+2020-04-02 08:26:47,274-INFO: Detection bbox results save in output/dog.jpg
+```
+
 ## 参考论文
 
 - [You Only Look Once: Unified, Real-Time Object Detection](https://arxiv.org/abs/1506.02640v5), Joseph Redmon, Santosh Divvala, Ross Girshick, Ali Farhadi.
diff --git a/yolov3/colormap.py b/yolov3/colormap.py
new file mode 100644
index 0000000000000000000000000000000000000000..af20f9348e2b06affa89c7cd32e87fc8f25ec706
--- /dev/null
+++ b/yolov3/colormap.py
@@ -0,0 +1,51 @@
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import numpy as np
+
+
+def colormap(rgb=False):
+    """
+    Get colormap
+    """
+    color_list = np.array([
+        0.000, 0.447, 0.741, 0.850, 0.325, 0.098, 0.929, 0.694, 0.125, 0.494,
+        0.184, 0.556, 0.466, 0.674, 0.188, 0.301, 0.745, 0.933, 0.635, 0.078,
+        0.184, 0.300, 0.300, 0.300, 0.600, 0.600, 0.600, 1.000, 0.000, 0.000,
+        1.000, 0.500, 0.000, 0.749, 0.749, 0.000, 0.000, 1.000, 0.000, 0.000,
+        0.000, 1.000, 0.667, 0.000, 1.000, 0.333, 0.333, 0.000, 0.333, 0.667,
+        0.000, 0.333, 1.000, 0.000, 0.667, 0.333, 0.000, 0.667, 0.667, 0.000,
+        0.667, 1.000, 0.000, 1.000, 0.333, 0.000, 1.000, 0.667, 0.000, 1.000,
+        1.000, 0.000, 0.000, 0.333, 0.500, 0.000, 0.667, 0.500, 0.000, 1.000,
+        0.500, 0.333, 0.000, 0.500, 0.333, 0.333, 0.500, 0.333, 0.667, 0.500,
+        0.333, 1.000, 0.500, 0.667, 0.000, 0.500, 0.667, 0.333, 0.500, 0.667,
+        0.667, 0.500, 0.667, 1.000, 0.500, 1.000, 0.000, 0.500, 1.000, 0.333,
+        0.500, 1.000, 0.667, 0.500, 1.000, 1.000, 0.500, 0.000, 0.333, 1.000,
+        0.000, 0.667, 1.000, 0.000, 1.000, 1.000, 0.333, 0.000, 1.000, 0.333,
+        0.333, 1.000, 0.333, 0.667, 1.000, 0.333, 1.000, 1.000, 0.667, 0.000,
+        1.000, 0.667, 0.333, 1.000, 0.667, 0.667, 1.000, 0.667, 1.000, 1.000,
+        1.000, 0.000, 1.000, 1.000, 0.333, 1.000, 1.000, 0.667, 1.000, 0.167,
+        0.000, 0.000, 0.333, 0.000, 0.000, 0.500, 0.000, 0.000, 0.667, 0.000,
+        0.000, 0.833, 0.000, 0.000, 1.000, 0.000, 0.000, 0.000, 0.167, 0.000,
+        0.000, 0.333, 0.000, 0.000, 0.500, 0.000, 0.000, 0.667, 0.000, 0.000,
+        0.833, 0.000, 0.000, 1.000, 0.000, 0.000, 0.000, 0.167, 0.000, 0.000,
+        0.333, 0.000, 0.000, 0.500, 0.000, 0.000, 0.667, 0.000, 0.000, 0.833,
+        0.000, 0.000, 1.000, 0.000, 0.000, 0.000, 0.143, 0.143, 0.143, 0.286,
+        0.286, 0.286, 0.429, 0.429, 0.429, 0.571, 0.571, 0.571, 0.714, 0.714,
+        0.714, 0.857, 0.857, 0.857, 1.000, 1.000, 1.000
+    ]).astype(np.float32)
+    color_list = color_list.reshape((-1, 3)) * 255
+    if not rgb:
+        color_list = color_list[:, ::-1]
+    return color_list
diff --git a/yolov3/dataset/voc/download.py b/yolov3/dataset/voc/download.py
new file mode 100644
index 0000000000000000000000000000000000000000..72976f7b03a871a13bb53fa952bccc671f967cf2
--- /dev/null
+++ b/yolov3/dataset/voc/download.py
@@ -0,0 +1,41 @@
+# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import tarfile
+
+from paddle.dataset.common import download
+
+DATASETS = {
+    'voc': [
+        ('https://paddlemodels.bj.bcebos.com/hapi/voc.tar',
+         '9faeb7fd997aeea843092fd608d5bcb4', ),
+    ],
+}
+
+def download_decompress_file(data_dir, url, md5):
+    logger.info("Downloading from {}".format(url))
+    tar_file = download(url, data_dir, md5)
+    logger.info("Decompressing {}".format(tar_file))
+    with tarfile.open(tar_file) as tf:
+        tf.extractall(path=data_dir)
+    os.remove(tar_file)
+
+
+if __name__ == "__main__":
+    data_dir = osp.split(osp.realpath(sys.argv[0]))[0]
+    for name, infos in DATASETS.items():
+        for info in infos:
+            download_decompress_file(data_dir, *info)
+
diff --git a/yolov3/image/YOLOv3.jpg b/yolov3/image/YOLOv3.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..06b81f545247c1d542fd661f947eb0cf3edc480e
Binary files /dev/null and b/yolov3/image/YOLOv3.jpg differ
diff --git a/yolov3/image/YOLOv3_structure.jpg b/yolov3/image/YOLOv3_structure.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..51bd2d1733e2f78945d3e871cb5b649aad95d633
Binary files /dev/null and b/yolov3/image/YOLOv3_structure.jpg differ
diff --git a/yolov3/image/dog.jpg b/yolov3/image/dog.jpg
new file mode 100644
index 0000000000000000000000000000000000000000..77b0381222eaed50867643f4166092c781e56d5b
Binary files /dev/null and b/yolov3/image/dog.jpg differ
diff --git a/yolov3/infer.py b/yolov3/infer.py
new file mode 100644
index 0000000000000000000000000000000000000000..612e5175181106f575bf2929ea1d1a7cf71e5e3b
--- /dev/null
+++ b/yolov3/infer.py
@@ -0,0 +1,125 @@
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import division
+from __future__ import print_function
+
+import os
+import argparse
+import numpy as np
+from PIL import Image 
+
+from paddle import fluid
+from paddle.fluid.optimizer import Momentum
+from paddle.fluid.io import DataLoader
+
+from model import Model, Input, set_device
+from modeling import yolov3_darknet53, YoloLoss
+from coco import COCODataset
+from transforms import *
+from visualizer import draw_bbox
+
+import logging
+logger = logging.getLogger(__name__)
+
+IMAGE_MEAN = [0.485, 0.456, 0.406]
+IMAGE_STD = [0.229, 0.224, 0.225]
+
+
+def get_save_image_name(output_dir, image_path):
+    """
+    Get save image name from source image path.
+    """
+    if not os.path.exists(output_dir):
+        os.makedirs(output_dir)
+    image_name = os.path.split(image_path)[-1]
+    name, ext = os.path.splitext(image_name)
+    return os.path.join(output_dir, "{}".format(name)) + ext
+
+
+def load_labels(label_list, with_background=True):
+    idx = int(with_background)
+    cat2name = {}
+    with open(label_list) as f:
+        for line in f.readlines():
+            line = line.strip()
+            if line:
+                cat2name[idx] = line
+                idx += 1
+    return cat2name
+
+
+def main():
+    device = set_device(FLAGS.device)
+    fluid.enable_dygraph(device) if FLAGS.dynamic else None
+    
+    inputs = [Input([None, 3], 'int32', name='img_info'),
+              Input([None, 3, None, None], 'float32', name='image')]
+
+    cat2name = load_labels(FLAGS.label_list, with_background=False)
+
+    model = yolov3_darknet53(num_classes=len(cat2name),
+                             model_mode='test',
+                             pretrained=FLAGS.weights is None)
+
+    model.prepare(inputs=inputs, device=FLAGS.device)
+
+    if FLAGS.weights is not None:
+        model.load(FLAGS.weights, reset_optimizer=True)
+
+    # image preprocess
+    orig_img = Image.open(FLAGS.infer_image).convert('RGB')
+    w, h  = orig_img.size
+    img = orig_img.resize((608, 608), Image.BICUBIC)
+    img = np.array(img).astype('float32') / 255.0
+    img -= np.array(IMAGE_MEAN)
+    img /= np.array(IMAGE_STD)
+    img = img.transpose((2, 0, 1))[np.newaxis, :]
+    img_info = np.array([0, h, w]).astype('int32')[np.newaxis, :]
+
+    _, bboxes = model.test([img_info, img])
+
+    vis_img = draw_bbox(orig_img, cat2name, bboxes, FLAGS.draw_threshold)
+    save_name = get_save_image_name(FLAGS.output_dir, FLAGS.infer_image)
+    logger.info("Detection bbox results save in {}".format(save_name))
+    vis_img.save(save_name, quality=95)
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser("Yolov3 Training on VOC")
+    parser.add_argument(
+        "--device", type=str, default='gpu', help="device to use, gpu or cpu")
+    parser.add_argument(
+        "-d", "--dynamic", action='store_true', help="enable dygraph mode")
+    parser.add_argument(
+        "--label_list", type=str, default=None,
+        help="path to category label list file")
+    parser.add_argument(
+        "-t", "--draw_threshold", type=float, default=0.5,
+        help="threshold to reserve the result for visualization")
+    parser.add_argument(
+        "-i", "--infer_image", type=str, default=None,
+        help="image path for inference")
+    parser.add_argument(
+        "-o", "--output_dir", type=str, default='output',
+        help="directory to save inference result if --visualize is set")
+    parser.add_argument(
+        "-w", "--weights", default=None, type=str,
+        help="path to weights for inference")
+    FLAGS = parser.parse_args()
+    assert os.path.isfile(FLAGS.infer_image), \
+            "infer_image {} not a file".format(FLAGS.infer_image)
+    assert os.path.isfile(FLAGS.label_list), \
+            "label_list {} not a file".format(FLAGS.label_list)
+    main()
diff --git a/yolov3/main.py b/yolov3/main.py
index 3dc77993c158b8dcef4d15d1861696f4db055034..8ea40eaa9c2ddc45d957ac8245d4552f4245a044 100644
--- a/yolov3/main.py
+++ b/yolov3/main.py
@@ -195,8 +195,6 @@ if __name__ == '__main__':
         help='initial learning rate')
     parser.add_argument(
         "-b", "--batch_size", default=8, type=int, help="batch size")
-    parser.add_argument(
-        "-n", "--num_devices", default=1, type=int, help="number of devices")
     parser.add_argument(
         "-j", "--num_workers", default=4, type=int, help="reader worker number")
     parser.add_argument(
diff --git a/yolov3/modeling.py b/yolov3/modeling.py
index b2a52026bbb7c781dbd340862f2c6e760c8cac1b..699fadb10a2cb6654f139f1014cfd11e4fb178b9 100644
--- a/yolov3/modeling.py
+++ b/yolov3/modeling.py
@@ -91,8 +91,8 @@ class YOLOv3(Model):
     def __init__(self, num_classes=80, model_mode='train'):
         super(YOLOv3, self).__init__()
         self.num_classes = num_classes
-        assert str.lower(model_mode) in ['train', 'eval'], \
-            "model_mode should be 'train' or 'val', but got " \
+        assert str.lower(model_mode) in ['train', 'eval', 'test'], \
+            "model_mode should be 'train' 'eval' or 'test', but got " \
             "{}".format(model_mode)
         self.model_mode = str.lower(model_mode)
         self.anchors = [10, 13, 16, 30, 33, 23, 30, 61, 62, 45,
@@ -157,7 +157,7 @@ class YOLOv3(Model):
                 route = self.route_blocks[idx](route)
                 route = fluid.layers.resize_nearest(route, scale=2)
 
-            if self.model_mode == 'eval':
+            if self.model_mode != 'train':
                 anchor_mask = self.anchor_masks[idx]
                 mask_anchors = []
                 for m in anchor_mask:
@@ -181,16 +181,21 @@ class YOLOv3(Model):
         if self.model_mode == 'train':
             return outputs
 
-        return outputs + [img_id[0, :], fluid.layers.multiclass_nms(
-                bboxes=fluid.layers.concat(boxes, axis=1),
-                scores=fluid.layers.concat(scores, axis=2),
-                score_threshold=self.valid_thresh,
-                nms_top_k=self.nms_topk,
-                keep_top_k=self.nms_posk,
-                nms_threshold=self.nms_thresh,
-                background_label=-1)
-]
-
+        preds = [img_id[0, :],
+                 fluid.layers.multiclass_nms(
+                    bboxes=fluid.layers.concat(boxes, axis=1),
+                    scores=fluid.layers.concat(scores, axis=2),
+                    score_threshold=self.valid_thresh,
+                    nms_top_k=self.nms_topk,
+                    keep_top_k=self.nms_posk,
+                    nms_threshold=self.nms_thresh,
+                    background_label=-1)]
+
+        if self.model_mode == 'test':
+            return preds
+
+        # model_mode == "eval"
+        return outputs + preds
 
 class YoloLoss(Loss):
     def __init__(self, num_classes=80, num_max_boxes=50):
diff --git a/yolov3/visualizer.py b/yolov3/visualizer.py
new file mode 100644
index 0000000000000000000000000000000000000000..1eb04f2dcf4f67604a9370ad4c6324e09c96f92f
--- /dev/null
+++ b/yolov3/visualizer.py
@@ -0,0 +1,69 @@
+# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import division
+from __future__ import print_function
+
+import numpy as np
+from PIL import Image, ImageDraw
+
+from colormap import colormap
+
+import logging
+logger = logging.getLogger(__name__)
+
+__all__ = ['draw_bbox']
+
+
+def draw_bbox(image, catid2name, bboxes, threshold):
+    """
+    Draw bbox on image
+    """
+    bboxes = np.array(bboxes)
+    if bboxes.shape[1] != 6:
+        logger.info("No bbox detect")
+        return image
+
+    draw = ImageDraw.Draw(image)
+
+    catid2color = {}
+    color_list = colormap(rgb=True)[:40]
+    for bbox in bboxes:
+        catid, score, xmin, ymin, xmax, ymax = bbox
+
+        if score < threshold:
+            continue
+
+        if catid not in catid2color:
+            idx = np.random.randint(len(color_list))
+            catid2color[catid] = color_list[idx]
+        color = tuple(catid2color[catid])
+
+        # draw bbox
+        draw.line(
+            [(xmin, ymin), (xmin, ymax), (xmax, ymax), (xmax, ymin),
+             (xmin, ymin)],
+            width=2,
+            fill=color)
+        logger.info("detect {} at {} score: {:.2f}".format(
+            catid2name[int(catid)], [xmin, ymin, xmax, ymax], score))
+
+        # draw label
+        text = "{} {:.2f}".format(catid2name[catid], score)
+        tw, th = draw.textsize(text)
+        draw.rectangle(
+            [(xmin + 1, ymin - th), (xmin + tw + 1, ymin)], fill=color)
+        draw.text((xmin + 1, ymin - th), text, fill=(255, 255, 255))
+
+    return image