High frequency GPS dynamic monitoring is capable of quickly calculating the surface displacement in quasi real time,which is helpful in supplement to the traditional seismology in the aspects of rapid determination of seismic parameters,short-term variation process of crustal deformation,focal rupture process and magnitude scaling. Based on the 1Hz GPS data in Zhejiang Province,we obtained the displacement time series of the M_W9.0 earthquake in Japan on March 11,2011 by using the track module of GAMIT. Then we compared the displacement signals obtained by the seismometers observed by the seismic network of Zhejiang Province with that from the displacement time series of GPS data. The results show that the difference between the peak ground motion displacement obtained by high frequency GPS and seismometer is within the range of GPS observation error. In the frequency range of 0.005～0.1Hz,the correlation coefficient of the two waveforms in horizontal direction is increased by more than 50%,and that in elevation direction is increased by more than 2 times. The results suggest that the observation of high frequency GPS and broadband seismometer overlaps each other in time sequence and frequency spectrum,and GPS and seismograph can cover the whole possible range of earthquake surface displacement.