By using the field measured data for the surface waves and the uplift pressures acted on the vertical breakwater at the observation station, the single spectra for the surface waves and the uplift pressures at various test points as well as the cross spectra, the functions of frequency response and coherence were calculated and thereby, they revealed the statistical characteristics of the uplift pressure acted on vertical breakwater and the relationship in which how the above-mentioned characteristics were related to the frequency, the phase and the magnitude among the surface waves in front of breakwater. Moreover, the observation equipment for the uplift pressure and distribution of location for test points were introduced also in this paper.