With　the　development　of　IC　technology,　the　system　which　increases　complexity　requires　design　at　a　higher　level　of　abstraction.　In　this　paper,　system-level　design　flow　and　modeling　methods　based　on　SystemC　for　complex　embedded　systems　are　introduced.　The　method　includes　the　hierarchical　modeling　methods,　object-oriented　modeling　technology,　and　the　＇Top-Down＇　modeling　methods,　and　provides　system-level　modeling　guidance　for　designers.　By　using　the　system-level　modeling　method,　the　speech　recognition　system　has　been　modeled　successfully,　and　the　performance　of　speech　recognition　system　has　been　analyzed.　The　performance　analysis　results　provide　an　effective　reference　on　refined　the　speech　recognition　algorithm　in　further.