Abstract: A method of performance optimization is proposed based on Markov process in Heterogeneous Wireless Networks (HWNs) consisting of diverse wireless networks. The method takes users mobility as an important factor affecting system performance, and users mobility is embodied by handoff rate. Then the system performance of HWNs based on Markov process is analyzed, and the expression of total throughput is obtained for the performance analysis of HWNs. Considering that the users in the overlapping region of two wireless networks need to select one of them to access, the proportion of service arrival rate accessing to one of the networks to the total service arrival rate in the overlapping region is regarded as an optimized factor for performance analysis. The throughput of the HWNs system is maximized by choosing appropriate factor. Finally, the optimization issue is worked out based on golden section method. The simulation results show that the optimization algorithm can effectively enhance the throughput of HWNs, and improve the resources utilization of wireless networks.