diff --git a/src/layer/concat.cpp b/src/layer/concat.cpp
index 6c1b9dc89..72b8bb3a5 100644
--- a/src/layer/concat.cpp
+++ b/src/layer/concat.cpp
@@ -24,6 +24,43 @@ Concat::Concat()
 
 int Concat::forward(const std::vector<Mat>& bottom_blobs, std::vector<Mat>& top_blobs) const
 {
+    int dims = bottom_blobs[0].dims;
+
+    if (dims == 1)
+    {
+        // concat vector
+        // total length
+        int top_w = 0;
+        for (size_t b=0; b<bottom_blobs.size(); b++)
+        {
+            const Mat& bottom_blob = bottom_blobs[b];
+            top_w += bottom_blob.w;
+        }
+
+        Mat& top_blob = top_blobs[0];
+        top_blob.create(top_w);
+        if (top_blob.empty())
+            return -100;
+
+        float* outptr = top_blob;
+        for (size_t b=0; b<bottom_blobs.size(); b++)
+        {
+            const Mat& bottom_blob = bottom_blobs[b];
+
+            int w = bottom_blob.w;
+
+            const float* ptr = bottom_blob;
+            for (int i=0; i<w; i++)
+            {
+                outptr[i] = ptr[i];
+            }
+
+            outptr += w;
+        }
+
+        return 0;
+    }
+
     int w = bottom_blobs[0].w;
     int h = bottom_blobs[0].h;