Abstract: This paper presents an example of slide-toppling deformation in the slope of Jin-chuan open pit mine. The composite mechanism and doformation process are controlled by the tabular-blocky structure on a faulted rock mass. The rheologic behaviour is found to be consistent with a three stage creep law and can be exprssed by an exponential function. The results of field investigations and long-term observation demonstrate that the time-dependent deformation of rock masses is essentially related to creep sliding along faults and other weak surfaces.