diff --git a/pcdet/ops/pointnet2/pointnet2_stack/src/group_points_gpu.h b/pcdet/ops/pointnet2/pointnet2_stack/src/group_points_gpu.h
new file mode 100644
index 0000000..4a26621
--- /dev/null
+++ b/pcdet/ops/pointnet2/pointnet2_stack/src/group_points_gpu.h
@@ -0,0 +1,31 @@
+/*
+Stacked-batch-data version of point grouping, modified from the original implementation of official PointNet++ codes.
+Written by Shaoshuai Shi
+All Rights Reserved 2019-2020.
+*/
+
+
+#ifndef _STACK_GROUP_POINTS_GPU_H
+#define _STACK_GROUP_POINTS_GPU_H
+
+#include <torch/serialize/tensor.h>
+#include <cuda.h>
+#include <cuda_runtime_api.h>
+#include <vector>
+
+
+int group_points_wrapper_stack(int B, int M, int C, int nsample,
+    at::Tensor features_tensor, at::Tensor features_batch_cnt_tensor,
+    at::Tensor idx_tensor, at::Tensor idx_batch_cnt_tensor, at::Tensor out_tensor);
+
+void group_points_kernel_launcher_stack(int B, int M, int C, int nsample,
+    const float *features, const int *features_batch_cnt, const int *idx, const int *idx_batch_cnt, float *out);
+
+int group_points_grad_wrapper_stack(int B, int M, int C, int N, int nsample,
+    at::Tensor grad_out_tensor, at::Tensor idx_tensor, at::Tensor idx_batch_cnt_tensor,
+    at::Tensor features_batch_cnt_tensor, at::Tensor grad_features_tensor);
+
+void group_points_grad_kernel_launcher_stack(int B, int M, int C, int N, int nsample,
+    const float *grad_out, const int *idx, const int *idx_batch_cnt, const int *features_batch_cnt, float *grad_features);
+
+#endif