diff --git a/paddle/fluid/API.spec b/paddle/fluid/API.spec
index 52af3ce51ba67c2b58c5e79c18c8d554e3c4b68c..108a7309db222f97dd3731cb07fa62d9c181b44c 100644
--- a/paddle/fluid/API.spec
+++ b/paddle/fluid/API.spec
@@ -328,6 +328,7 @@ paddle.fluid.layers.polygon_box_transform (ArgSpec(args=['input', 'name'], varar
 paddle.fluid.layers.yolov3_loss (ArgSpec(args=['x', 'gtbox', 'gtlabel', 'anchors', 'anchor_mask', 'class_num', 'ignore_thresh', 'downsample_ratio', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '991e934c3e09abf0edec7c9c978b4691'))
 paddle.fluid.layers.box_clip (ArgSpec(args=['input', 'im_info', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '397e9e02b451d99c56e20f268fa03f2e'))
 paddle.fluid.layers.multiclass_nms (ArgSpec(args=['bboxes', 'scores', 'score_threshold', 'nms_top_k', 'keep_top_k', 'nms_threshold', 'normalized', 'nms_eta', 'background_label', 'name'], varargs=None, keywords=None, defaults=(0.3, True, 1.0, 0, None)), ('document', 'ca7d1107b6c5d2d6d8221039a220fde0'))
+paddle.fluid.layers.distribute_fpn_proposals (ArgSpec(args=['fpn_rois', 'min_level', 'max_level', 'refer_level', 'refer_scale', 'name'], varargs=None, keywords=None, defaults=(None,)), ('document', '41ef443800fa2976299e73e788336cae'))
 paddle.fluid.layers.accuracy (ArgSpec(args=['input', 'label', 'k', 'correct', 'total'], varargs=None, keywords=None, defaults=(1, None, None)), ('document', '9808534c12c5e739a10f73ebb0b4eafd'))
 paddle.fluid.layers.auc (ArgSpec(args=['input', 'label', 'curve', 'num_thresholds', 'topk', 'slide_steps'], varargs=None, keywords=None, defaults=('ROC', 4095, 1, 1)), ('document', 'e0e95334fce92d16c2d9db6e7caffc47'))
 paddle.fluid.layers.exponential_decay (ArgSpec(args=['learning_rate', 'decay_steps', 'decay_rate', 'staircase'], varargs=None, keywords=None, defaults=(False,)), ('document', '98a5050bee8522fcea81aa795adaba51'))
diff --git a/python/paddle/fluid/layers/detection.py b/python/paddle/fluid/layers/detection.py
index 9475e0f21768d27bc6526a7fb86e373520bfc8a8..9dc5e1e9e295d67845bd076f06a32e1896c12c24 100644
--- a/python/paddle/fluid/layers/detection.py
+++ b/python/paddle/fluid/layers/detection.py
@@ -2233,22 +2233,16 @@ def distribute_fpn_proposals(fpn_rois,
     """
     Distribute all proposals into different fpn level, with respect to scale 
     of the proposals, the referring scale and the referring level. Besides, to
-    restore the order of proposals, we return an array which indicate the 
+    restore the order of proposals, we return an array which indicates the 
     original index of rois in current proposals. To compute fpn level for each 
     roi, the formula is given as follows:
     
     .. code-block:: text
 
-        roi_scale = sqrt(BBoxArea(fpn_roi));
-        level = floor(log2(roi_scale / refer_scale) + refer_level)
-    
-    where BBoxArea is the function to compute the area of each roi:
+        roi_scale = \sqrt{BBoxArea(fpn_roi)};
+        level = \floor{\log \frac{roi_scale}{refer_scale} + refer_level}
 
-    .. code-block:: text
-    
-        w = fpn_roi[2] - fpn_roi[0]
-        h = fpn_roi[3] - fpn_roi[1]
-        area = (w + 1) * (h + 1)
+    where BBoxArea is the area of each roi
 
     Args:
         fpn_rois(variable): The input fpn_rois, the last dimension is 4.
@@ -2258,7 +2252,8 @@ def distribute_fpn_proposals(fpn_rois,
                         come from.
         refer_level(int): The referring level of FPN layer with specified scale.
         refer_scale(int): The referring scale of FPN layer with specified level.
-        
+        name(str|None): The name of this operator.        
+
     Returns:
         tuple: 
                A tuple(multi_rois, restore_ind) is returned. The multi_rois is