diff --git a/mmdet/core/eval/__init__.py b/mmdet/core/evaluation/__init__.py
similarity index 100%
rename from mmdet/core/eval/__init__.py
rename to mmdet/core/evaluation/__init__.py
diff --git a/mmdet/core/eval/bbox_overlaps.py b/mmdet/core/evaluation/bbox_overlaps.py
similarity index 100%
rename from mmdet/core/eval/bbox_overlaps.py
rename to mmdet/core/evaluation/bbox_overlaps.py
diff --git a/mmdet/core/eval/class_names.py b/mmdet/core/evaluation/class_names.py
similarity index 100%
rename from mmdet/core/eval/class_names.py
rename to mmdet/core/evaluation/class_names.py
diff --git a/mmdet/core/eval/coco_utils.py b/mmdet/core/evaluation/coco_utils.py
similarity index 100%
rename from mmdet/core/eval/coco_utils.py
rename to mmdet/core/evaluation/coco_utils.py
diff --git a/mmdet/core/eval/eval_hooks.py b/mmdet/core/evaluation/eval_hooks.py
similarity index 98%
rename from mmdet/core/eval/eval_hooks.py
rename to mmdet/core/evaluation/eval_hooks.py
index 870830ef3960cad77786546708d1836d7b5ae663..a83b80dbfe7081fa6dbfc13f818339c565076000 100644
--- a/mmdet/core/eval/eval_hooks.py
+++ b/mmdet/core/evaluation/eval_hooks.py
@@ -7,13 +7,12 @@ import mmcv
 import numpy as np
 import torch
 from mmcv.runner import Hook, obj_from_dict
+from mmcv.parallel import scatter, collate
 from pycocotools.cocoeval import COCOeval
 from torch.utils.data import Dataset
 
 from .coco_utils import results2json, fast_eval_recall
-from ..parallel import scatter
 from mmdet import datasets
-from mmdet.datasets.loader import collate
 
 
 class DistEvalHook(Hook):
diff --git a/mmdet/core/eval/mean_ap.py b/mmdet/core/evaluation/mean_ap.py
similarity index 100%
rename from mmdet/core/eval/mean_ap.py
rename to mmdet/core/evaluation/mean_ap.py
diff --git a/mmdet/core/eval/recall.py b/mmdet/core/evaluation/recall.py
similarity index 100%
rename from mmdet/core/eval/recall.py
rename to mmdet/core/evaluation/recall.py
diff --git a/mmdet/core/losses/__init__.py b/mmdet/core/loss/__init__.py
similarity index 100%
rename from mmdet/core/losses/__init__.py
rename to mmdet/core/loss/__init__.py
diff --git a/mmdet/core/losses/losses.py b/mmdet/core/loss/losses.py
similarity index 100%
rename from mmdet/core/losses/losses.py
rename to mmdet/core/loss/losses.py