diff --git a/mmdet3d/apis/inference.py b/mmdet3d/apis/inference.py
index 78dfa1e03a..bd9ed33332 100644
--- a/mmdet3d/apis/inference.py
+++ b/mmdet3d/apis/inference.py
@@ -7,11 +7,11 @@
 from mmcv.runner import load_checkpoint
 from os import path as osp
 
-from mmdet3d.core import (Box3DMode, DepthInstance3DBoxes,
-                          LiDARInstance3DBoxes, show_multi_modality_result,
-                          show_result, show_seg_result)
+from mmdet3d.core import (Box3DMode, CameraInstance3DBoxes,
+                          DepthInstance3DBoxes, LiDARInstance3DBoxes,
+                          show_multi_modality_result, show_result,
+                          show_seg_result)
 from mmdet3d.core.bbox import get_box_type
-from mmdet3d.core.bbox.structures.cam_box3d import CameraInstance3DBoxes
 from mmdet3d.datasets.pipelines import Compose
 from mmdet3d.models import build_model
 
@@ -427,11 +427,8 @@ def show_proj_det_result_meshlab(data,
             raise NotImplementedError(
                 'camera intrinsic matrix is not provided')
 
-        from mmdet3d.core.bbox import mono_cam_box2vis
         show_bboxes = CameraInstance3DBoxes(
             pred_bboxes, box_dim=pred_bboxes.shape[-1], origin=(0.5, 1.0, 0.5))
-        # TODO: remove the hack of box from NuScenesMonoDataset
-        show_bboxes = mono_cam_box2vis(show_bboxes)
 
         show_multi_modality_result(
             img,
diff --git a/mmdet3d/core/bbox/structures/utils.py b/mmdet3d/core/bbox/structures/utils.py
index 8870cb4260..fe63f9de11 100644
--- a/mmdet3d/core/bbox/structures/utils.py
+++ b/mmdet3d/core/bbox/structures/utils.py
@@ -1,5 +1,6 @@
 import numpy as np
 import torch
+from logging import warning
 
 
 def limit_period(val, offset=0.5, period=np.pi):
@@ -167,6 +168,9 @@ def mono_cam_box2vis(cam_box):
     Returns:
         :obj:`CameraInstance3DBoxes`: Box after conversion.
     """
+    warning.warn('DeprecationWarning: The hack of yaw and dimension in the '
+                 'monocular 3D detection on nuScenes has been removed. The '
+                 'function mono_cam_box2vis will be deprecated.')
     from . import CameraInstance3DBoxes
     assert isinstance(cam_box, CameraInstance3DBoxes), \
         'input bbox should be CameraInstance3DBoxes!'
diff --git a/mmdet3d/datasets/nuscenes_mono_dataset.py b/mmdet3d/datasets/nuscenes_mono_dataset.py
index f5ed089821..05c82539ad 100644
--- a/mmdet3d/datasets/nuscenes_mono_dataset.py
+++ b/mmdet3d/datasets/nuscenes_mono_dataset.py
@@ -11,7 +11,7 @@
 from mmdet3d.core import bbox3d2result, box3d_multiclass_nms, xywhr2xyxyr
 from mmdet.datasets import DATASETS, CocoDataset
 from ..core import show_multi_modality_result
-from ..core.bbox import CameraInstance3DBoxes, get_box_type, mono_cam_box2vis
+from ..core.bbox import CameraInstance3DBoxes, get_box_type
 from .pipelines import Compose
 from .utils import extract_result_dict, get_loading_pipeline
 
@@ -624,9 +624,6 @@ def show(self, results, out_dir, show=True, pipeline=None):
             img = img.numpy().transpose(1, 2, 0)
             gt_bboxes = self.get_ann_info(i)['gt_bboxes_3d']
             pred_bboxes = result['boxes_3d']
-            # TODO: remove the hack of box from NuScenesMonoDataset
-            gt_bboxes = mono_cam_box2vis(gt_bboxes)
-            pred_bboxes = mono_cam_box2vis(pred_bboxes)
             show_multi_modality_result(
                 img,
                 gt_bboxes,
diff --git a/mmdet3d/models/detectors/single_stage_mono3d.py b/mmdet3d/models/detectors/single_stage_mono3d.py
index 0ed3bb5157..bf033b8744 100644
--- a/mmdet3d/models/detectors/single_stage_mono3d.py
+++ b/mmdet3d/models/detectors/single_stage_mono3d.py
@@ -5,7 +5,7 @@
 from os import path as osp
 
 from mmdet3d.core import (CameraInstance3DBoxes, bbox3d2result,
-                          mono_cam_box2vis, show_multi_modality_result)
+                          show_multi_modality_result)
 from mmdet.models.builder import DETECTORS
 from mmdet.models.detectors.single_stage import SingleStageDetector
 
@@ -207,9 +207,6 @@ def show_results(self, data, result, out_dir):
             assert isinstance(pred_bboxes, CameraInstance3DBoxes), \
                 f'unsupported predicted bbox type {type(pred_bboxes)}'
 
-            # TODO: remove the hack of box from NuScenesMonoDataset
-            pred_bboxes = mono_cam_box2vis(pred_bboxes)
-
             show_multi_modality_result(
                 img,
                 None,
diff --git a/setup.cfg b/setup.cfg
index c2b6d98937..8b615d27cf 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -8,6 +8,6 @@ line_length = 79
 multi_line_output = 0
 known_standard_library = setuptools
 known_first_party = mmdet,mmseg,mmdet3d
-known_third_party = cv2,indoor3d_util,load_scannet_data,lyft_dataset_sdk,m2r,matplotlib,mmcv,nuimages,numba,numpy,nuscenes,pandas,plyfile,pycocotools,pyquaternion,pytest,recommonmark,scannet_utils,scipy,seaborn,shapely,skimage,tensorflow,terminaltables,torch,trimesh,waymo_open_dataset
+known_third_party = cv2,imageio,indoor3d_util,load_scannet_data,lyft_dataset_sdk,m2r,matplotlib,mmcv,nuimages,numba,numpy,nuscenes,pandas,plyfile,pycocotools,pyquaternion,pytest,recommonmark,scannet_utils,scipy,seaborn,shapely,skimage,tensorflow,terminaltables,torch,trimesh,waymo_open_dataset
 no_lines_before = STDLIB,LOCALFOLDER
 default_section = THIRDPARTY