Stanford University Interim Channel Model serial was proposed to simulate the fixed broadband wireless access channel environments where IEEE802.16d is to be deployed. This channel model serial embraces 6 channel models that are grouped into 3 categories according to 3 typical different outdoor terrains. On the other hand, IEEE802.16d Wireless-MAN system demands for a robust synchronization mechanism to guarantee its transmission reliability. To satisfy this requirement, an improved iterative joint synchronization algorithm for time offset and frequency offset is used, which is based on the time-domain preamble given by IEEE802.16d standard. Since the synchronization performance is closely related to a given channel model, our research focuses on the simulation performance of this iterative joint synchronization algorithm through different channel models in 256 Orthogonal Frequency Division Multiplexing of IEEE8O2.16d Wireless-MAN system. The simulation results show that this iterative joint synchronization could effectively reduce the probability of synchronization failure, and it is not sensitive to the channel models in the most flat and intermediate terrain types. In the hilly terrains, i.e. channel models with large channel spread delay, the irreducible probability of synchronization failure doesn't occur by using this iterative joint algorithm.