Abstract Using the conclusion of aftershocks relocation, inversion on seismic wave and InSAR results, and surface rupture displacement obtained by geological survey after the earthquake, this paper constructs a faults model of Yushu MsT. 1 earthquake. Based on rectangular dislocation theory in elastic-viscoelastic layering medium, we have simulated the co-seismic deformation and gravity change with gravitational effect considered. The pictures show that the absolute gravity measuring point is beside the extremum of coseismic gravity change, and the numerical value reach to 25.02 × 10-Sm·s-2. After a discussion about the gravity changes before the earthquake and the coherence consistency between two FG-5 absolute gravimeters, we think that the measured value 27.2 × 10-Sm·s-2 at Yushu station is coseismic gravity change. It＇s coincident with the simulation results based on dislocation theory. So it＇s good inspection to the near-field changes on dislocation theory.