Abstract: Objective To detect the spatiotemporal cluster of human immunodeficiency virus/acquired immunodeficiency syndrome(HIV/AIDS)in Guangxi Zhuang Autonomous Region(Guangxi)from 2005 through 2012.Methods Spatial empirical Bayesian smoothing(SEBS)was used to smooth the notified incidence of HIV/AIDS at county level from 2005 through 2012 in Guangxi.HIV/AIDS spatiotemporal clusters were identified by using spatiotemporal scan statistics and Poisson model and then were visualized via Geographic Information System(GIS).Results The areas with the most serious HIV/AIDS epidemics,including urban area and some counties of Liuzhou and Hezhou city and some counties in southwest region adjacent to Vietnam,were identified with both thematic maps of notified incidence adjusted by SEBS and spatiotemporal scan statistics.There were six spatiotemporal clusters of HIV/AIDS notified incidence in Guangxi from 2005 through 2012.Among the clusters,the first-level cluster areas centered on Luzhai county and covered 17 counties(cities/districts),with the clustering time from November 2010 through September 2012(log likelihood ratio(LLR)=1886.21,relative risk(RR)=2.97;P=0.00);the main second-level cluster areas centered on Shangsi county,including 20 counties(cities/districts),with the clustering time from March 2010 through September 2011(LLR=944.69,RR=2.00;P=0.00);the other cluster areas centered on Gangnan district of Guigang city and covered 11 counties(cities/districts),with the clustering time from March 2011through May 2012.Conclusion Spatiotemporal scan statistics could be applied to reveal the spatiotemporal clusters of HIV/AIDS in Guangxi.Health departments should strengthen the prevention and control of HIV/AIDS in the areas with spatiotemporal clustering of the epidemic.