The high topography Tibetan plateau is generated by India–Eurasia collision since Cenozoic. A high resolution shear wave velocity model can provide better understanding of the tectonic evolution of southern Tibet. Based on the continuous seismic observations of about 400 stations, we collected over 20000 Rayleigh wave group velocity dispersion curves extracted from ambient noise cross- correlation functions. A direct surface-wave inversion method is applied to obtain S-velocity model of Tibetan crust and upper-most mantle. A heterogeneous structure including several low-velocity zones (LVZs) of southern Tibet is revealed. Our result shows significant distinction of mid-lower crust structure between eastern and western part of the Lhasa terrane. We propose that the LVZs of western Lhasa terrane may be resulted by crustal shortening since the India-Eurasia collision. Meanwhile, the LVZs of middle crust in the eastern part of Lhasa terrane are related to tectonic event in deeper structure and may be attributed to tearing of subducted lithosphere.