Abstract: Based on the establishment of the spatial databases and its system for the southeastern active tectonic zone of the Tibetan Plateau, the authors gathered earthquake information of this region from 1980 to 2013 and geohazards as well as national fundamental geographic information. Using the script writing and spatial model, the authors made a statistic analysis of the seismic activity information in this region from 1980 to 2013. Based on the principle of negative correlation between regional seismic b-value and crust internal stress distribution, the authors employed a large-area temporal-spatial scanning method based on b-value to detect current stress state of the southeastern margin of the Tibetan Plateau and, in combination with the study of active structure, to provide a clue to seismic hazard discussion. Considering the spatial difference of the seismic statistical samples, the authors divided the study area into several districts of 2°×2° grid cells, and then calculated the b-value for every unit and every year. The study focused on low b-value areas, summarized b-value temporal-spatial regularity and curves and, in combination with the former study of seismic gap, made a comprehensive mid-long-term seismic hazard prediction. Some conclusions have been reached:①Wenchuan earthquake and Lushan earthquake demonstrate that before and after the marcoquake the b-value time curve will change in order of horizontal-negative growth-positive growth-negative growth-horizontal; ② the greater the earthquake magnitude, the earlier the formation of the low value dangerous area of the b-value negative growth and the longer the duration; ③ before Wenchuan earthquake, a large area of low b-value anomaly appeared in northern Sichuan; ④ at present, the low b-value areas that have lasted for quite a long time include eastern Himalayan syntaxis, Yushu-Garze fault, Anninghe fault-Zemuhe fault-Xianshuihe-fault-Xiaojing fault and Wanting fault-Nantinghe fault, and there exists quite a lot of overlapping between Lancang fault-Jinghong fault and the predicted seismic open risk area.