The states of local seismic activity and seismic tendency have been studied by using time progress analytical method to the historical seismic data in Gansu and Shanxi region.The results are as follow:(1) The active and quiet periods of local strong earthquakes with M_S7.0 have occurred alternatively in different time scales.(2) In the active periods of strong earthquakes with M_S≥ 7.0,the activities of moderate strong events have accompanied the occurrence of strong earthquakes with M_S≥ 7.0,but they have accompanied the occurrence of earthquakes with M_S6.0 or have occurred as cluster of events with M_S≥ 5.0 in the quiet periods.(3) The seismic states of Gansu may be in the quiet period of both strong earthquakes with M_S7.0 and moderate strong earthquakes,and the probability of occurrence of strong earthquakes with M_S≥ 7.0 is small within one or serveral hundred years,meanwhile,the probability of occurrence of moderate strong events is also small over ten years from now.