Abstract:On the basis of mobile gravity observation data from 1998 to 2008 in western Sichuan, spatial dynamic variation results of regional gravity field are obtained, the relations between the gravity variation features and Wenchuan Ms8.0 earthquake are systematically analysised.The results show: 1)gravity change is closely related to active fault tectonics, gravity measurement can reflect material migration accompanying active fault and crustal tectonic activity well. 2) The regional gravity variations in a wide range appeared during Wenchuan earthquake. The dynamic patterns of gravity field mirrored the evolution process of gravity field :quasihomogeneous statenonhomogeneous stateearthquake occurence.