diff --git a/test/registered/core/test_gpt_oss_sm120.py b/test/registered/core/test_gpt_oss_sm120.py
new file mode 100644
index 000000000..ee2f05716
--- /dev/null
+++ b/test/registered/core/test_gpt_oss_sm120.py
@@ -0,0 +1,34 @@
+import unittest
+
+import torch
+
+from sglang.test.ci.ci_register import register_cuda_ci
+from sglang.test.gpt_oss_common import BaseTestGptOss
+
+register_cuda_ci(est_time=500, suite="stage-b-test-small-1-gpu")
+
+
+@unittest.skipIf(not torch.cuda.is_available(), "CUDA is not available")
+class TestGptOssSm120(BaseTestGptOss):
+    @classmethod
+    def setUpClass(cls):
+        compute_capability = torch.cuda.get_device_capability()
+        if compute_capability != (12, 0):
+            raise unittest.SkipTest(
+                f"GPT-OSS SM120 test requires SM 12.0, but found {compute_capability[0]}.{compute_capability[1]}"
+            )
+
+    def test_mxfp4_20b(self):
+        self.run_test(
+            model_variant="20b",
+            quantization="mxfp4",
+            expected_score_of_reasoning_effort={
+                "low": 0.34,
+                "medium": 0.34,
+                "high": 0.27,
+            },
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()