Abstract:Deep rock is located in definite geological environment. Therefore,the conditions of temperature and pressure have especially important influence on the mechanical properties. Based on the conditions of temperature and pressure,the geothermic character and ground pressure of the deep formations of Carbonic and Triassic sandstone in Tahe oil field of Talimu basin are researched. The effects of different temperatures and pressures under deep conditions on mechanical property of sandstone are studied by using triaxial rock mechanics experimental system;and the relative relationships between the mechanical properties of sandstone and temperature or confining pressure are established. It is shown that the mechanical properties of sandstone are closely related to its temperature and effective confining pressure. The stiffness and strength of the sandstone decrease with temperature increasing;and the residual strength after rock failure also reduces when temperature increases. The stiffness and strength of sandstone increase with confining pressures increasing and the failure mechanism of the rock transforms with the increase of confining pressure.