Abstract：On the basis of the absolute and relative gravity observations of the national major scientific project—China Crustal Movement Observation Network from 1998 to 2008，gravity field and its dynamic variations of Yushu earthquake are obtained, and the evolution characteristics of regional gravity field and its relation with the seismic activity before and after Yushu Ms7.1 earthquake occurred on April 14,2010 are studied in the sight of dynamics. The results show as follows. 1)The gravity change are closely related to GanziYushu active fault i.e., the gravity observation can reflect material migration accompanying active fault and crustal tectonic activity well. 2)The dynamic variation images of gravity field reflect the anomalous informations of the gravity field observed with mobile survey with the development and occurrence of Yushu Ms7.1 earthquake clearly. 3)Temporal changes of gravity points nearby Yushu epicenter amount to more than 80×10 -8 ms -2 ,it reflected wavelike rises with gravity change before Yushu earthquake in time.
