The present invention relates to an apparatus and method of frame synchronization in broad band wireless communication systems. In an apparatus of frame synchronization in a mobile station, a time variant phase rotation compensator eliminates time variant phase rotation carried in received signals by conjugated multiplication between adjacent signal samples. Then, the processed signal is fed into a delay correlator to calculate a plurality of correlations between two successive frames. A local power calculator acquires an average power of several symbols centered on delayed correlation values. A normalizer normalizes the delayed correlation values with a local average power corresponding to the delayed correlation values. A maximum value detector selects the maximum value from normalized correlation values to trigger frame synchronizing and timing signals.