diff --git a/i18n_guardian/detectors/react_intl.py b/i18n_guardian/detectors/react_intl.py
new file mode 100644
index 0000000..4414ebd
--- /dev/null
+++ b/i18n_guardian/detectors/react_intl.py
@@ -0,0 +1,77 @@
+"""React Intl detector."""
+
+import json
+from pathlib import Path
+from typing import Optional
+
+from i18n_guardian.detectors.base import Detector
+
+
+class ReactIntlDetector(Detector):
+    """Detect React Intl (react-intl) library usage."""
+
+    @property
+    def name(self) -> str:
+        return "react-intl"
+
+    @property
+    def patterns(self) -> list:
+        return ["package.json", "webpack.config.js", ".babelrc", ".babelrc.js"]
+
+    def detect(self, path: Path) -> Optional[str]:
+        """Check for React Intl usage."""
+        package_json = path / "package.json"
+        if package_json.exists():
+            try:
+                with open(package_json, "r", encoding="utf-8") as f:
+                    data = json.load(f)
+                    dependencies = data.get("dependencies", {})
+                    dev_dependencies = data.get("devDependencies", {})
+                    all_deps = {**dependencies, **dev_dependencies}
+                    if "react-intl" in all_deps or "格式化消息" in str(all_deps):
+                        return self.name
+            except (json.JSONDecodeError, OSError):
+                pass
+
+        webpack_config = path / "webpack.config.js"
+        if webpack_config.exists():
+            try:
+                content = webpack_config.read_text(encoding="utf-8")
+                if "react-intl" in content or "FormattedMessage" in content:
+                    return self.name
+            except OSError:
+                pass
+
+        babelrc = path / ".babelrc"
+        if babelrc.exists():
+            try:
+                with open(babelrc, "r", encoding="utf-8") as f:
+                    content = f.read()
+                    if "react-intl" in content:
+                        return self.name
+            except (json.JSONDecodeError, OSError):
+                pass
+
+        for js_file in path.rglob("*.js"):
+            try:
+                content = js_file.read_text(encoding="utf-8")
+                if "import { defineMessages } from 'react-intl'" in content or "import { FormattedMessage } from 'react-intl'" in content:
+                    return self.name
+            except OSError:
+                continue
+
+        return None
+
+    def get_i18n_functions(self) -> list:
+        """Get React Intl function names."""
+        return [
+            "formatMessage",
+            "defineMessages",
+            "FormattedMessage",
+            "FormattedDate",
+            "FormattedTime",
+            "FormattedRelativeTime",
+            "FormattedNumber",
+            "FormattedPlural",
+            "FormattedHTMLMessage",
+        ]