diff --git a/.coveragerc b/.coveragerc
new file mode 100644
index 000000000..5a0a37805
--- /dev/null
+++ b/.coveragerc
@@ -0,0 +1,16 @@
+[run]
+source = python/sglang/srt
+omit =
+    */test/*
+    */__pycache__/*
+
+[report]
+show_missing = true
+exclude_lines =
+    pragma: no cover
+    if __name__ == .__main__.:
+    raise NotImplementedError
+    if TYPE_CHECKING
+
+[html]
+directory = htmlcov
diff --git a/python/pyproject.toml b/python/pyproject.toml
index 9b2613ddb..6a05dbf7d 100755
--- a/python/pyproject.toml
+++ b/python/pyproject.toml
@@ -141,6 +141,8 @@ test = [
   "parameterized",
   "peft",
   "pytest",
+  "pytest-cov",
+  "diff-cover",
   "sentence_transformers",
   "tabulate",
 ]
diff --git a/test/registered/unit/README.md b/test/registered/unit/README.md
index e2d6aa5dd..ec8dc218b 100644
--- a/test/registered/unit/README.md
+++ b/test/registered/unit/README.md
@@ -22,6 +22,15 @@ Tests can use CPU or GPU — the key criterion is **no server process**.
    pytest test/registered/unit/ -v            # all unit tests
    pytest test/registered/unit/mem_cache/ -v  # one module
    ```
+5. Run with coverage:
+   ```bash
+   # summary
+   pytest test/registered/unit/ --cov --cov-config=.coveragerc -v
+
+   # PR incremental check (require ≥60% on changed lines)
+   pytest test/registered/unit/ --cov --cov-config=.coveragerc --cov-report=xml
+   diff-cover coverage.xml --compare-branch=origin/main --fail-under=60
+   ```
 
 ## Example