Abstract: In this paper the authors have analyzed the data of mobile geodetic deformation along the middle and southern segments of South-North Seismic Belt and studied the spatial distribution and characteristics of fault activity in recent time. The results show that the fault activity rate a long Honghe-Chuxiong-Tonghai fault and Xianshuihe fault is the hig hest and Longmenshan fault is the slow est. Fault activity levels in the recent years have not intensified or become weaker in general. Through studies the authors put forw ard several viewpoints as follows: Regional fault activity strengthens before strong earthquakes. Sudden fault displacement possesses an important part of fault movement, which exhibited in the geologic data. Along southern segment of South-North Seismic Belt in the near future there will keep the same state of high frequency of strong earthquake occurrence as in the past 20 years. Along the middle segment of South-North Seismic Belt there is a possibility that the earthquake with M_S=6 may occur in recent years. The middle of Chuxiong-Tonghai fault and the two ends of Xianshuihe fault are risk locations of strong earthquakes, which deserve the notice.

Key words: Fault displacement rate, Seismicity, South-North Seismic Belt