Abstract: Based on analyzing the characteristics of active tectonics and stress field in Southwest China region, the statistical correlation between moderately strong earthquakes along Litang-Dewu fault and great earthquakes in Sichuan-Yunnan and its neighboring areas reveals that among 6 earthquakes with M>5.5 occurred along Litang-Dewu fault during 1900~2000, there were 5 earthquakes, after each of which 2~3 years, a strong earthquake with M>7.5 occurred on the boundary zone of the Sichuan-Yunnan rhombic block and its adjacent region. On the contrary, there were totally 7 earthquakes with M>7.5 occurred in Southwest China region, among which 2~3 years before each of 5 earthquakes, there were earthquakes with M<5.5 occurred along Litang-Dewu fault. On the basis of the statistical data the author discussed the influence of Yajiang earthquake with M=6.0 on Feb.23, 2001 on recent tendency in Southwest China region.

Key words: Sichuan-Yunnan rhombic block, Yajiang earthquake, Earthquake tendency