Abstract: In this paper we discuss the seismogenic process of a great earthquake by using a rheolo-gic model of rock. We regard the constant strain rate as the condition of seismogeny for a great earthquake. On the basis of analytic results, the curves of variation of stress, strain, strain rate and energy with time are calculated. Upon such curves, the stage features of the seismogenic process of a great earthquake is analyzed. And the possible mechanisms of the various seismic precursory phenomena is emphatically discussed, and the relation between the pre-seismic anomalous phenomena and the seismogenic process is given.