Synthetic Aperture Radar Interferometry (InSAR) provides an invaluable approach to detect the substantial surface deformation due to the Yushu earthquake (Mw=7.1) on April 14, 2010. The crustal deformation that occurred on April 14, 2010 is recorded by the ALOS satellite in ascending passes. Co-seismic deformation field of Yushu earthquake is extracted based on the ALOS/PALSAR data acquired with a large temporal separation, which followed the southeast to northwest direction, with the maximum deformation 57.8cm and 55.1cm in LOS (line of sight) direction occurring respectively in the northern and southern part of the Yushu-Ganzi fault directly from the interferogram. Deformation field is important for prediction of the associated seismic hazards in the vicinity of large seismogenic faults. Analysis of surface deformation indicates that most of the seismic moment release along the 82-km-long rupture and the rupture breaks the surface. The locations of the epicenters derived from the InSAR result agree well with that from field investigation. It approves that D-InSAR technology is a invaluable alternative method to locate the epicenter and quickly predict the magnitude of an earthquake.