Using the method of receiver function, based on the data of digital seismic stations in Gansu province, the crustal structure beneath digital seismic stations in Gansu province is studied. The results indicate that the depth of Moho is about 50 km in the study area, and the Moho＇s depth of the southern Gansu is deeper than the western Gansu. The crust under Gansu province consists of two layers, the interface is at about 20 km. A low velocity layer is ubiquitous in upper crust, it formed not because the partial melting of rock but the geophysical and geochemical factors. Otherwise, the velocities of earth＇s surface are very different beneath different stations.