Objective: To investigate the situations of AIDS related knowledge, sexual behavior with various partners among HIV positive patients in Shenzhen before highly active anti-retroviral therapy, and to provide evidences for health education intervention. Methods: Questionnaire survey and information collection were carried out among HIV positive patients, under the informed consent, during the first physical examination before highly active anti-retroviral therapy. Results: The overall awareness rate of AIDS knowledge was 91%, 94.46% and 80.95% respectively for homosexual and heterosexual populations, with significant difference between the two groups (χ²=21.254, P<0.001). In addition, there were significant differences in the factors related to education, income, route of infection, marital status, residence and other related factors (P<0.05). In HIV positive MSM, primary sexual behavior occurred mainly at the age of less than 30 (96.8%) and in university or earlier stage (58.3%), college students as the first sexual partner accounted for 44.9%, and once used Rush accounted for 42.7%. There were significant differences in the number of temporary sexual partners and condom use frequency between homosexual and heterosexual subjects (P<0.05). Conclusions Individuals infected with HIV via different routes are variant on AIDS cognition. Health education on AIDS related knowledge and sexual security before and after antiviral treatment can not only improve the awareness rate of HIV/AIDS infection, but also can reduce the risk of the spread of HIV/AIDS.