Objective: To analyze associated factors of HIV infection among college students who are young men and have sex with men (YMSM) in Tianjin, providing reference for HIV prevention and control among YMSM college students. Methods: During Aug. 1st, 2018 to Dec. 31st, 2018, SHENLAN recruited college students who were YMSM aged 18-24 years from gay baths, gay bars, QQ, WeChat and gay dating app BLUED. HIV infection status and associated factors (general demographic characteristics, unsafe sexual behaviors, addictive substance using, basic knowledge of HIV) was collected and analyzed. Results: A total of 470 college students, including 21 HIV infected (4.47%), were enrolled in this study. Univariate Logistic regression analyses indicated that age, age at first sex behavior, HIV related knowledge, tobacco use, recreational drug usage, syphilis infection was associated with HIV infection among YMSM students (P<0.05). Multivariate analysis found age of first sex (OR=21.20，95%CI=3.09-145.43), recreational drug use (OR=5.07，95%CI=1.77-14.48), lack of HIV related knowledge (OR=3.38，95%CI=1.33-8.63)were associated with HIV infection (P<0.05). Conclusion College students who are YMSM in Tianjin have a high rate of HIV infection, who deserves further attention. Targeted campus HIV/AIDS prevention program should be developed combined with specific characteristics of this population.