The seamless internetworking among multiple heterogeneous networks is in demand to provide "always-on" connectivity services with QoS provision quality, anywhere, anytime. The hybrid networks of WLAN and WMAN can provide high data rate and enhanced multimedia services, but it is challenging to obtain optimized handover decision based dynamic QOS information. The IEEE 802.21 aims at providing a framework that defines Media Independent Handover (MIH) mechanism that supports seamless handover across heterogeneous networks. In this paper, we propose a MADM handover decision algorithm with QOS provision across WLAN and WMAN. The simulation results show that the proposed algorithm provides smaller handover times and lower dropping rate than basic vertical handover methods.