A method was presented to numerical simulate the transient response of rotor tilting pad journal bearing elastic foundation system,which considered the influences of the journal vibration on the dynamic characteristics of the tilting pad journal bearing,and the effect of temperature and flow regime change was also included.The kinetic equations of rotor tilting pad journal bearings elastic foundation were deduced,and the effects of the elastic foundation on the transient response of rotor tilting pad journal bearing system were studied.The results show that dynamic characteristics of the tilting pad journal bearing will change the rotors axis locus.The rotor system transient response is increased along with the decreasing of the foundation stiffness,and the amplitude of the response curve of axis locus is decreased along with the increasing of the foundation damping.The increasing of the damping will not change the convergent position of the rotors axis trajectory at stable state.