Abstract: Longling-Lancang fault zone in southwestern Yunnan is an area with strong seismicity. Multi strong earthquakes with M_S≥7.0 hit the area and nearly ruptured the whole fault zone during last 100 years. This paper summarized characteristics of recent tectonic activities and calculated b value of the studied area first of all, and then combined with the distribution of historical strong earthquakes and modern small ones, the fault activity since Late Quaternary and elapse time to analyze the potential seismic risk in the future synthetically. Finally, based on the seismic gap theory, the seismic gaps in the fault zone are identified. The results show that the Longling, Yongde, Cangyuan, Lancang along the fault zone and middle-east segment of Menglian fault have a potential of moderate-strong earthquake occurrence in the future ten years.