In this investigation，aiming at the problem of low-frequency wave inducing harbor oscillations，the effects of the variation of the spectral peak frequency （fp1） and significant wave height （Hs1） of low-frequency spectral on the resonance within the harbor are systematically investigated by a physical model experiment. The experimental results show that：1）The closer fp1 is to the first resonance frequency of the harbor，the stronger the low-frequency wave response is. The first resonance frequency of the harbor can be accurately identified by fp1 amplification factor curve. Simultaneously，the variation of Hs1 mainly affects the wave response of the first resonance mode. 2）Based on the squared-wavelet-based bicoherence spectra，it is found that the closer fp1 is to the first resonance frequency of the harbor or the larger Hs1 is，the stronger the nonlinear wave interaction is. The study results will play a good role in guiding the construction of the sea harbor where the swell and wind waves coexist for a long time.