Some researches have been made in this aspect.In the method by Walton Jr.(1992),incidentwaves are supposed to be the overlapping result of M component waves with different frequencies whichmay take different directions,the direction of incident waves should be available in advance,but in fact thedirection of incident waves is not available.In our study,incident waves are supposed to be composed ofM overlapping component waves with different frequencies,and different frequencies have different direc-tions.Based on the irregular wave reflection theory,the calculation formulas of wave direction,complexamplitude of incident waves,and complex amplitude of reflected waves in surface which are composed ofcomponent waves are derived by means of discrete Fourier transform.Then,the frequency spectra of inci-dent waves and reflected waves and the reflection coefficient of waves with corresponding frequencies areobtained.Verification of the method and the calculation results from in-situ measured data indicate thatt Some researches have been made in this aspect. The method by Walton Jr. (1992), incidentwaves are supposed to be the overlapping result of M component waves with different frequencies whichmay take different directions, the direction of incident waves should be available in advance , but in fact thedirection of incident waves is not available. our study, incident waves are supposed to be composed of M overlapping component waves with different frequencies, and different frequencies have different directivities. the basis of the irregular wave reflection theory, the calculation formulas of wave direction, complexamplitude of incident waves, and complex amplitude of reflected waves in surface which are composed ofcomponents waves are derived by means of discrete Fourier transform. Then, the frequency spectra of inci-dent waves and reflected waves and the reflection coefficient of waves with corresponding frequencies areobtained. Verification of the method and the calculation results from in-situ measured data indicate thatt