Handoff is an important research topic of mobility support protocols. It has great effects on the performance and quality-of-service of mobile networks. Based on appropriate network model and handoff model, the handoff performance of various mobility support protocols is deeply studied and compared through theoretical analysis and numerical simulation. The comparisons are made between mobile IP and micro-mobility protocol, and between different micro-mobility protocols. The results show that wireless network parameters and route update algorithms of mobility support protocols affect the handoff performance. The handoff performance when applying micro-mobility protocols is better than when only using Mobile IP. In all micro-mobility protocols, the route update algorithm of MIP-RR and MMP has the optimal performance.