Abstract: Objective To examine the characteristics of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic in Liaoning province and to provide evidences for effective prevention and control of HIV/AIDS in the province. Methods Data on HIV/AIDS cases reported in Liaoning province from 1993 through 2015 were extracted from Comprehensive AIDS Prevention and Control Information System of China Disease Control and Prevention System and analyzed statistically.Results By the end of 2015,totally 11 839 HIV/AIDS cases were reported in Liaoning province,with 3 509 AIDS patients and 1 461 deaths. The reported HIV/AIDS cases distributed in all 14 municipalities across the province,but more than 50% of the total cases were reported in Shenyang and Dalian municipality. More male cases were reported with a cumulative male to female ratio of 11.5:1. About one third (31.27%) of the reported cases were at the ages of 21-30 years;the cumulative ratio of the cases aged 21-30 years were 31.27% and the ratio significantly increased yearly (χ_trend²=481.96,P<481.96). Among the reported cases,the main transmission route was unsafe sexual behavior and the estimated accumulative proportion of HIV infection through sexuall transmission was 92.58%;in addition,the ratio of HIV infection through male-to-male sexual transmission showed a yearly increasing trend (χ_trend²=609.5,P<0.001).Conclusion In Liaoning province,the HIV/AIDS epidemic increases yearly and the reported HIV/AIDS cases distribute in various regions;sexual transmission has become a major route of HIV spread and the ratio of male-to-male sexual transmission is relatively high in Liaoning province.