Abstract: Objective：To investigate the prevalence of infection with AIDS-related mycoplasma, including Mycoplasma genitalium (Mg), Mycoplasma fermentans (Mf), Mycoplasma penetrans (Mpe) and Mycoplasma pirum (Mpi), in male HIV carriers and AIDS patients in Jiangsu province, and analyze the correlation between the infection of mycoplasma and the development of AIDS to provide the evidences for the role of AIDS-related mycoplasma in the alterations of immune function in latent HIV carriers and AIDS patients. Methods：A cross-sectional epidemiological questionnaire survey was performed for 312 male HIV carriers and AIDS patiets following informed consent. The first void urine and venous blood samples from the males included in this study were collected. Mycoplasma was detected with PCR, CD4⁺ T lymphocyte was measured with flow cytometry and the level of cytokines was determined by ELISA. Results: Among the studied males, 3 species of AIDS-related mycoplasma were detectable except Mpe with infection rates of 26.9%, 13.8% and 21.8% for Mg, Mf and Mpi respectively. There were significant differences of the infection rates of Mf among different CD4⁺ T cell levels (χ² =11.775, P=0.003). The level of IL-4 (4.437 pg/mL) in the males who were infected by both of HIV and mycoplasma was significantly higher than that in the males with single HIV infection (1.922 pg/mL), but the level of IL-6 (0.431 pg/mL) in the males with complicated infection was lower than that of the single HIV infection (0.532 pg/mL) (P<0.001). Multiple factor logistic regression analysis showed that the risk of AIDS related mycoplasma infection in south Jiangsu was higher than that in north Jiangsu (OR=2.388, 95%CI: 1.212 4.706) and middle Jiangsu (OR=0.447, 95%CI: 0.253 0.790). The risk of AIDS related mycoplasma infection in the males undergoing active antiretroviral treatment was the lower than that without ART (OR=0.545, 95%CI: 0.311 0.955). Conclusion: It was noted that high pathogenic mycoplasma infection was found in the males with HIV-latent infection and AIDS patients in Jiangsu province. The mycoplasma infection correlated with the host immune status.