Abstract:GPS is widely used in geodetic survey of geophysical exploration.its accuracy may be centimeter level or even higher.In the paper GPS gravity method is put forward to determine elevation because the problem of positive elevation or normal elevation(adopted in China)still can not be resolved in the three-dimensional coordinate system determined by GPS.The paper details the principle,application and accuracy of this method.In practice,the elevation error between two points whose distance is more than 100 km is less than 20.2cm.It is obvious that such accuracy can meet the requirement of geophysical exploration in complicated terrain.