Objective To know about the marital status of men who have sex with men (MSM) in Chongqing and Sichuan area, and to explore the impact of marital status on acquired immune deficiency syndrome (AIDS)-related knowledge and attitude, acceptance of health service, AIDS-related high-risk behavior and human immunodeficiency virus (HIV)/sexually transmited disease (STD) infection. Methods A total of 1 240 MSM participants were recruited from Sichuan and Chongqing area using the nonrandom sampling method, and they were surveyed through an anonymous questionnaire, and their AIDS-related knowledge and attitude, acceptance of health service, AIDS-related high-risk behavior were investigated. The HIV antibody was detected by gold standard rapid diagnosis method and enzyme-linked immunosorbent assay. Chi-square test was adopted for rate comparison among groups. The age and AIDS-related knowledge were compared between groups by rank sum test. Results Significant differences were detected in age, residence registration type, education level, employment status, and personal average monthly income between married group and unmarried group (P<0.05). The median AIDS related knowledge score for the unmarried group was 9 (inter-quartile range 4), which was significantly higher than that of the married group (8[inter-quartile range 5], P<0.05). It was found that 53.8% of the participants in the married group deemed that MSM population had a high HIV infection rate in their area, while the number was 58.0% in the unmarried group. The proportion of participants in the married group who thought AIDS was a great threat to their family was significantly higher than that in the unmarried group (P<0.05). We found that 40.5% MSM in the married group never had the HIV testing, which was significantly higher than that in the unmarried group (34.3%, P<0.05). AIDS-related high-risk sexual behaviors were similar in the two groups. The HIV-infection rate in the married group was 30.9%, being significantly higher than that in the unmarried group (21.1%, P<0.05). Conclusion Marriage does not reduce the frequency of AIDS-related high-risk sexual behavior among MSM population. The high HIV-infection rate in MSM people in the married group indicates a higher risk for HIV transmission from MSM population to normal people.