Abstract:On March 21th, 2008, a MS7.3 earthquake occurred in Yutian of Xinjiang. In this paper, InSAR technology is used to obtain the coseismic and postseismic deformation. The inversion of coseismic slip distribution shows that the largest slip achieves 5.4 m and that the slip is dominant in the south of the fault, near 0-5 km depth beneath the ground surface. The earthquake is a normal faulting event with a slight sinistral strike-slip component. Postseismic deformation indicates that there are differences in movement in the north section of seismogenic fault, and the largest cumulative deformation difference is about 15 cm in 782 d after the earthquake. According to the further analysis, the afterslip of postseismic fault may be the main mechanism for deformation. The degree of postseismic afterslip is relatively small in two years and the slip region decreases greatly and for the most part is located in shallow areas. The energy of north fault is relatively exhaustive released, while there is little energy remaining in south part of the fault.