OBJECTIVE: To understand the characteristics and trends of HIV and syphilis infections among drug users. METHODS: Information was collected regarding HIV and syphilis epidemics, as well as on high risk behaviors from the HIV/AIDS surveillance system. Source of information was from HIV/AIDS case-reporting, sentinel surveillance and trend estimation, related to the changes of distribution among HIV positive drug users prevalence rates on HIV and syphilis together with their high risk behaviors. RESULTS: Scale number on drug users remained stable in the past six year (from 2003 - 2009), while the proportion of drug users decreased from 44.2% in 2005 to 25.8% in 2009. Based on the information from HIV/AIDS case reporting system, HIV sentinel surveillance data showed that the HIV prevalence of drug users was quite different from those of Southwestern to Northeastern parts of China. The HIV prevalence in Southwestern China was much higher than that of the Northeastern areas. Sentinel surveillance data showed that the average positive rates were 6.2% and 3.7% on HIV and syphilis, among the drug users. As for injecting drug users (IDU), the average rates on HIV antibody syphilis and HCV were 9.2% and 4.0% respectively. Series surveillance data indicated that the HIV epidemic expanded quickly among drug users from 1995 - 1999 but became plateaued after 2000 among the IDUs. HIV antibody positive rate remained at 9.0% - 10.0% in the past three years while syphilis fluctuated between 3.5% - 4.5% in the past three years. CONCLUSION: Drug users and IDUs still remained an important driven factor for HIV/AIDS epidemic in China, suggesting more specific strategies and methods should be developed, based on the characteristics and trends of HIV epidemic, to optimize the allocation HIV prevention and control resources.