Driver＇s　fatigue　detection　has　been　realized　based　on　driver＇s　mouth　geometrical　features.　It　can　give　some　information　when　driver　is　fatigue.　For　better　speed　and　reliability,　a　new　method　which　was　based　on　combined　Adaboost　algorithm　and　particle　filter　was　applied.　Then　the　mouth　verification　was　applied　according　to　prior　knowledge.　Driver＇s　state　was　judged　by　the　geometrical　features　in　a　period　of　time.　As　a　result,　the　detection　accuracy　was　improved.　This　method　can　meet　the　requirement　of　driver＇s　fatigue　detection.