The semi-theoretical and semi-experimental relation between wavelength and distance between station pairs for array of microtremors was presented.Based on previous theoretical and experimental results

it is pointed out that the dominant direction exists in microtremors wave field

i.e.there are phase differences among microtremors’ records from each channel in the range of effective wavelength.The phase correction method and expressions for projecting to some direction were presented and the time delay correction of correlation function and phase velocity curves of SPAC method was achieved.A case study shows that the method proposed is effective.