diff --git a/testsuite/c_test/sanity_test/SANITY0027-convert/convert.c b/testsuite/c_test/sanity_test/SANITY0027-convert/convert.c
new file mode 100644
index 0000000000000000000000000000000000000000..f86b630dfd1a7c9ca9ceb4ff93e499f09699d883
--- /dev/null
+++ b/testsuite/c_test/sanity_test/SANITY0027-convert/convert.c
@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) [2021] Futurewei Technologies, Inc. All rights reverved.
+ *
+ * Licensed under the Mulan Permissive Software License v2.
+ * You can use this software according to the terms and conditions of the MulanPSL - 2.0.
+ * You may obtain a copy of MulanPSL - 2.0 at:
+ *
+ *   https://opensource.org/licenses/MulanPSL-2.0
+ *
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR
+ * FIT FOR A PARTICULAR PURPOSE.
+ * See the MulanPSL - 2.0 for more details.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+char c = 0xff;
+unsigned char uc = 0xff;
+short s;
+int i;
+long long l;
+
+int main()
+{
+  s = c;
+  i = s;
+  l = i;
+  //printf("signed = %ld ", l);
+  if (l != -1) {
+    abort();
+  }
+
+  s = uc;
+  i = s;
+  l = i;
+  //printf("unsigned = %ld\n", l);
+  if (l != 255) {
+    abort();
+  }
+
+  return 0;
+}
diff --git a/testsuite/c_test/sanity_test/SANITY0027-convert/test.cfg b/testsuite/c_test/sanity_test/SANITY0027-convert/test.cfg
new file mode 100644
index 0000000000000000000000000000000000000000..55fe4332d1435c7430d176b932eaac901b0ab3be
--- /dev/null
+++ b/testsuite/c_test/sanity_test/SANITY0027-convert/test.cfg
@@ -0,0 +1,3 @@
+clean()
+compile(convert)
+run(convert)