In order to further understand the changing face of China's HIV/AIDS epidemic, and facilitate a tailored response, the Chinese Ministry of Health (MOH), together with the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) has generated new estimates and a report for 2011. The US Center for Disease Control and Prevention (US CDC) has provided technical support on the estimates. As with previous estimation exercises (from 2005 to 2009), the Workbook model has been used as the primary estimation method. In addition, Estimation and Projection Package (EPP)/Spectrum methods have been employed to verify annual estimates of new HIV infections and AIDS deaths.