diff --git a/base_matrix/base_matrix_concatenate.hpp b/base_matrix/base_matrix_concatenate.hpp
index 00e7034..701737e 100644
--- a/base_matrix/base_matrix_concatenate.hpp
+++ b/base_matrix/base_matrix_concatenate.hpp
@@ -24,7 +24,7 @@ struct VerticalConcatenateLoop {
   static void compute(const Matrix<T, M, N> &A, const Matrix<T, P, N> &B,
                       Matrix<T, M + P, N> &Y) {
     Base::Utility::copy<T, 0, M, 0, M, (M + P)>(A.data[Row], Y.data[Row]);
-    Base::Utility::copy<T, 0, P, M, M, (M + P)>(B.data[Row], Y.data[Row]);
+    Base::Utility::copy<T, 0, P, M, P, (M + P)>(B.data[Row], Y.data[Row]);
     VerticalConcatenateLoop<T, M, P, N, Row - 1>::compute(A, B, Y);
   }
 };
@@ -35,7 +35,7 @@ struct VerticalConcatenateLoop<T, M, P, N, 0> {
   static void compute(const Matrix<T, M, N> &A, const Matrix<T, P, N> &B,
                       Matrix<T, M + P, N> &Y) {
     Base::Utility::copy<T, 0, M, 0, M, (M + P)>(A.data[0], Y.data[0]);
-    Base::Utility::copy<T, 0, P, M, M, (M + P)>(B.data[0], Y.data[0]);
+    Base::Utility::copy<T, 0, P, M, P, (M + P)>(B.data[0], Y.data[0]);
   }
 };
 
@@ -56,7 +56,7 @@ inline void update_vertically_concatenated_matrix(Matrix<T, M + P, N> &Y,
 
   for (std::size_t row = 0; row < N; row++) {
     Base::Utility::copy<T, 0, M, 0, M, (M + P)>(A.data[row], Y.data[row]);
-    Base::Utility::copy<T, 0, P, M, M, (M + P)>(B.data[row], Y.data[row]);
+    Base::Utility::copy<T, 0, P, M, P, (M + P)>(B.data[row], Y.data[row]);
   }
 
 #else // __BASE_MATRIX_USE_FOR_LOOP_OPERATION__
diff --git a/test_vs/check_python_numpy.hpp b/test_vs/check_python_numpy.hpp
index 5908888..a6bf8a4 100644
--- a/test_vs/check_python_numpy.hpp
+++ b/test_vs/check_python_numpy.hpp
@@ -1303,6 +1303,44 @@ void CheckPythonNumpy<T>::check_python_numpy_concatenate(void) {
 
 
     /* 結合 */
+    Matrix<DefDense, T, 1, 1> a({ {1} });
+    Matrix<DefDense, T, 1, 1> b({ {2} });
+    Matrix<DefDense, T, 2, 1> aa({ {1}, {2} });
+    Matrix<DefDense, T, 2, 1> bb({ {3}, {4} });
+
+    auto a_v_b = concatenate_vertically(a, b);
+
+    Matrix<DefDense, T, 2, 1> a_v_b_answer({
+        {1},
+        {2}
+        });
+
+    tester.expect_near(a_v_b.matrix.data, a_v_b_answer.matrix.data, NEAR_LIMIT_STRICT,
+        "check concatenate vertically Dense and Dense small, 1 1.");
+
+    auto aa_v_b = concatenate_vertically(aa, b);
+
+    Matrix<DefDense, T, 3, 1> aa_v_b_answer({
+        {1},
+        {2},
+        {2}
+        });
+
+    tester.expect_near(aa_v_b.matrix.data, aa_v_b_answer.matrix.data, NEAR_LIMIT_STRICT,
+        "check concatenate vertically Dense and Dense small, 2 1.");
+
+    auto a_v_bb = concatenate_vertically(a, bb);
+
+    Matrix<DefDense, T, 3, 1> a_v_bb_answer({
+        {1},
+        {3},
+        {4}
+        });
+
+    tester.expect_near(a_v_bb.matrix.data, a_v_bb_answer.matrix.data, NEAR_LIMIT_STRICT,
+        "check concatenate vertically Dense and Dense small, 1 2.");
+
+
     auto A_v_A = concatenate_vertically(A, A);
     ConcatenateVertically_Type<decltype(A), decltype(A)> A_v_A_t;
     A_v_A_t = A_v_A;