Abstract: Through uniaxial and triaxial compression and creep experiment of rock salt under on high temperature and high pressure, the strength and time dependent properties of rock salt are studied. The results indicate that rock salt is a typical soft rock. The mechanical characteristics of rock salt is strongly dependent on confined pressure. Transient creep limit is a power function of steady state creep strain rate. Through the creep characteristic curves and parameters, the creep constitutive equation of rock salt is regressed and agrees with the experiment result.