diff --git a/onnx/defs/nn/defs.cc b/onnx/defs/nn/defs.cc
index 881c1a1bcf3..f9a50002ccc 100644
--- a/onnx/defs/nn/defs.cc
+++ b/onnx/defs/nn/defs.cc
@@ -741,6 +741,8 @@ void convTransposeShapeInference(InferenceContext& ctx) {
     return;
   }
 
+  int64_t group = getAttribute(ctx, "group", 1);
+
   auto input_shape = ctx.getInputType(0)->tensor_type().shape();
   if (input_shape.dim_size() < 2) {
     return; // Input tensor should have at least two dimensions.
@@ -751,7 +753,11 @@ void convTransposeShapeInference(InferenceContext& ctx) {
 
   std::vector<int64_t> dilations;
   if (getRepeatedAttribute(ctx, "dilations", dilations)) {
-    return; // we don't handle the dialations.
+    for (auto i : dilations)
+    {
+      if (i != 1)
+        return; // we don't handle dialations not 1.
+    }
   }
 
   std::vector<int64_t> pads;
@@ -788,10 +794,13 @@ void convTransposeShapeInference(InferenceContext& ctx) {
   }
 
   std::vector<int64_t> output_shape;
+  bool output_shape_presented = true;
   if (getRepeatedAttribute(ctx, "output_shape", output_shape)) {
     if (output_shape.size() != n_input_dims) {
       return;
     }
+  } else {
+    output_shape_presented = false;
   }
 
   std::vector<int64_t> output_padding;
@@ -809,37 +818,39 @@ void convTransposeShapeInference(InferenceContext& ctx) {
   *final_output_shape->add_dim() = input_shape.dim(0);
   *final_output_shape->add_dim() =
       ctx.getInputType(1)->tensor_type().shape().dim(
-          1); // channels should be the second dim of second input.
+          1) * group; // channels should be the second dim of second input multiply group.
 
-  int size_of_output = static_cast<int>(output_shape.size());
-  if (size_of_output > 0) {
+  int size_of_output;
+  if (output_shape_presented) {
+    size_of_output = static_cast<int>(output_shape.size());
     for (int i = 0; i < size_of_output; ++i) {
-      if (output_shape[i] < input_shape.dim(i + 2).dim_value()) {
-        // TODO: throw exception?
-        return; // output shape value cannot be smaller than the input shape
-                // value
+      if (input_shape.dim(i + 2).has_dim_value()) {
+        if (output_shape[i] < input_shape.dim(i + 2).dim_value()) {
+          // TODO: throw exception?
+          return; // output shape value cannot be smaller than the input shape
+                  // value
+        }
       }
-
       final_output_shape->add_dim()->set_dim_value(output_shape[i]);
     }
-    return; // assume no need to proceed further when the output shape is given.
+    return;
   }
-
-  int kernel_shape_size = static_cast<int>(kernel_shape.size());
-  for (int i = 0; i < kernel_shape_size; ++i) {
-    auto newdim = final_output_shape->add_dim();
-    if (!input_shape.dim(2 + i).has_dim_value()) {
-      continue;
+  else
+  {
+    size_of_output = input_shape.dim_size() - 2;
+    for (int i = 0; i < size_of_output; ++i)
+    {
+      if (input_shape.dim(i + 2).has_dim_value()) {
+        int64_t output_shape_dim =
+            strides[i] * (input_shape.dim(i + 2).dim_value() - 1) +
+            output_padding[i] + kernel_shape[i] - pads[i] -
+            pads[i + n_input_dims];
+        final_output_shape->add_dim()->set_dim_value(output_shape_dim);
+      } else{
+        final_output_shape->add_dim();
+      }
     }
-
-    int64_t newdim_value =
-        strides[i] * (input_shape.dim(2 + i).dim_value() - 1);
-    newdim_value += (output_padding[i] + kernel_shape[i]);
-    newdim_value -= pads[i];
-    newdim_value -= pads[i + kernel_shape_size];
-
-    // add in the initial position
-    newdim->set_dim_value(newdim_value);
+    return;
   }
 }
 
diff --git a/onnx/test/shape_inference_test.py b/onnx/test/shape_inference_test.py
index 473438e60c6..a3773d94bd8 100644
--- a/onnx/test/shape_inference_test.py
+++ b/onnx/test/shape_inference_test.py
@@ -993,6 +993,22 @@ def test_conv_transpose_with_kernel_shape(self):  # type: () -> None
             [])
         self._assert_inferred(graph, [make_tensor_value_info('Y', TensorProto.FLOAT, (25, 32, 30, 30))])
 
+    def test_conv_transpose_with_group(self):  # type: () -> None
+        graph = self._make_graph(
+            [('X', TensorProto.FLOAT, (25, 48, 16, 16)),
+             ('W', TensorProto.FLOAT, (48, 32, 3, 3))],
+            [make_node('ConvTranspose', ['X', 'W'], 'Y', strides=[2, 2], pads=[1, 1, 2, 2], group=2)],
+            [])
+        self._assert_inferred(graph, [make_tensor_value_info('Y', TensorProto.FLOAT, (25, 64, 30, 30))])
+
+    def test_conv_transpose_with_group_and_output_shape(self):  # type: () -> None
+        graph = self._make_graph(
+            [('X', TensorProto.FLOAT, (25, 48, 16, 16)),
+             ('W', TensorProto.FLOAT, (48, 32, 3, 3))],
+            [make_node('ConvTranspose', ['X', 'W'], 'Y', strides=[2, 2], pads=[1, 1, 2, 2], group=2, output_shape=[36, 36])],
+            [])
+        self._assert_inferred(graph, [make_tensor_value_info('Y', TensorProto.FLOAT, (25, 64, 36, 36))])
+
     def test_mvn_function_output_shape(self):  # type: () -> None
         graph = self._make_graph(
             [('X', TensorProto.FLOAT, (25, 48, 16, 16))],