Abstract: In the years 1973 and 1981 two major earthquakes of respectively magnitudes 7.9 and 6.9 occurred at Luhuo and Daofu on the Xiaushuihe fault of Sichuan Province. In this paper, by analysing the data of geodetic measurements of ground surface deformation, accumulated in several years, on six short levelling and base lines crossing the major earthquake fault fracture and fault traces, the relation between the characteristics of fault movement and occurrence of the earthquakes have been studied. Preliminary discussion on earthquake prediction by geodetic measurment across earthquake faults has been attempted.