diff --git a/mmcv/ops/deform_conv.py b/mmcv/ops/deform_conv.py
index c31418528e..eb4b4e6f5a 100644
--- a/mmcv/ops/deform_conv.py
+++ b/mmcv/ops/deform_conv.py
@@ -57,7 +57,8 @@ def _npu_backward(ctx, grad_output):
                 input_tensor, grad_output, offset_out, weight, offset_all,
                 kernel_size=[weight.shape[3], weight.shape[2]],
                 stride=[1, 1, ctx.stride[0], ctx.stride[1]],
-                padding=[1, 1, ctx.padding[0], ctx.padding[1]],
+                padding=[ctx.padding[0], ctx.padding[0], ctx.padding[1],
+                         ctx.padding[1]],
                 dilation=[1, 1, ctx.dilation[0], ctx.dilation[1]],
                 groups=ctx.groups, deformable_groups=ctx.deform_groups,
                 modulated=True)
diff --git a/mmcv/ops/modulated_deform_conv.py b/mmcv/ops/modulated_deform_conv.py
index c631cf0a6b..dcdada47bd 100644
--- a/mmcv/ops/modulated_deform_conv.py
+++ b/mmcv/ops/modulated_deform_conv.py
@@ -64,7 +64,9 @@ def _npu_forward(ctx, input_tensor, offset, mask, weight, bias):
             conv2d_bias,
             kernel_size=[kernel_w, kernel_h],
             stride=[1, 1, ctx.stride[0], ctx.stride[1]],
-            padding=[1, 1, ctx.padding[0], ctx.padding[1]],
+            padding=[
+                ctx.padding[0], ctx.padding[0], ctx.padding[1], ctx.padding[1]
+            ],
             dilation=[1, 1, ctx.dilation[0], ctx.dilation[1]],
             groups=ctx.groups,
             deformable_groups=ctx.deform_groups,
@@ -84,7 +86,8 @@ def _npu_backward(ctx, grad_output):
                 input_tensor, grad_output, offset_out, weight, offset_all,
                 kernel_size=[weight.shape[3], weight.shape[2]],
                 stride=[1, 1, ctx.stride[0], ctx.stride[1]],
-                padding=[1, 1, ctx.padding[0], ctx.padding[1]],
+                padding=[ctx.padding[0], ctx.padding[0], ctx.padding[1],
+                         ctx.padding[1]],
                 dilation=[1, 1, ctx.dilation[0], ctx.dilation[1]],
                 groups=ctx.groups, deformable_groups=ctx.deform_groups,
                 modulated=True)