Abstract: Using the model data for surface mass changes of atmosphere, ocean, soil moisture and snow depth, the vertical crustal displacements of 25 ficual stations in China are calculated. From spectral analysis of the results, we can see that the periods of displacements are 12 months and the semi-periods are 6 months. The results also show that the maximum seasonal displacements can reach 20 mm and even larger. The covariance and significance tests show that the coefficients of 96 percent of stations are significant at the 99% significance level, which implies the perfect linear correlativity and coherence. The results show that one of reasons of the vertical cncstaldisplace ments is the changing surface fluid coads.