Objective To estimate the HIV/AIDS epidemic and treatment demand and predict the situation in the next ifve years with Spectrum. Methods Using Spectrum (version:3.54) to estimate the number of new HIV infections, number of people living with HIV, need for ART in adults and children, need for PMTCT and cotrimoxazole in Beijing and Hunan Province. Data used in the model including high-risk populations monitoring data and demographic information, was collected from Beijing Center for Disease Control and Prevention, Hunan Center for Disease Control and Prevention and extracted from statistical yearbooks and published literatures. Results Few new HIV/AIDS were reported in Beijing prior to 1994, however, the number of HIV infections was increasing rapidly from 1995 to 2008, and decreased after that, increased rapidly again after 2012. The number of patients who need antiretroviral treatment was increasing among the group aged between 15-49 years with young patients aged 15-24 years peaked in 2010 and decreased rapidly after that. Few HIV-infected patients were reported before 1997 in Hunan Province, and the number of new infections was increasing rapidly since 1998. The number of patients who need antiretroviral treatment was increasing among the group aged between 15-49 years since 2000 with young patients aged 15-24 years in need of antiretroviral therapy increasing continuously. Conclusions After HIV infection was ifrst founded in Beijing and Hunan Province, there was a slow growth and then a rapid growth of HIV epidemic. According to prediction of Spectrum, the demand for antiretroviral therapy in Beijing would begin to decline since 2011, meanwhile, the HIV epidemic in Hunan Province would enter a rapid growth period with the demand for antiviral therapy continuing to increase. In this study, Spectrum was applied to estimate the HIV epidemic situation and need for treatment in the next ifve years in Beijing and Hunan Province. It provides the basis for health resource allocation and policy formulation of HIV management.