Abstract: Based on the available geological and geophysical evidences as well as the geodyna-mics of basin and range structure, the current deformation and stress state in a simplified tectonic profile crossing northeasternly the Xizang plateau, about 2,000km long and 80 km deep, have been analysed using finite element method. Numerical results show that the Indian plate motion is the driving force to disturb the gravity equilibrium leading to a lateral density contrast, but the horizontal compression resulting from the isostatic adjustment is the mechanism for plateau uplift and earthquake development, and that stresses often concentrate at the main fault ends near the low velocity layer.Electrical conductivity measurements of 2-mica gneiss under temperature and pressure conditions equivalent to about 40km deep, together with the optical determination and the X-ray diffraction analysis, indicate that the mechanical weakening due to the dehydration, accompanied with lattice breaking of muscovite and the thermal cracking of quartz may be the mechanisms of forming the low velocity-low resistivity layer in the plateau crust, but the shear movement existing along the low velocity layer seems to be the source of raising its temperature.