Abstract: By high precision data processing,we obtain the coordinate time series of GPS continuous observation stations,which were located in the seismic area along the Longmen Shan Fault after the 2008 Wenchuan earthquake.Through the time series analysis,the postseismic relaxation time is 38 d,and postseismic displacements of these stations are obtained simultaneously.Based on the viscoelastic relaxation model,the thickness of the elastic layer and the coefficient of viscosity of the viscoelastic layer in Longmen Shan area,are inverted by simulating the observed postseismic displacements.The preferred values of the thickness of the elastic layer and the coefficient of viscosity of the viscoelastic layer are 45 km and 1.8×10¹⁹ Pa·s separately,which are in general accord with the results obtained by seismological and geophysical methods.