Abstract： Objective:To investigate the usage of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in Beijing, and analyze the related factors of using PrEP.Methods:MSM were recruited as study subjects through a mobile dating application in Beijing, and a cross-sectional survey was conducted using a self-designed online questionnaire to collect basic information, sexual behavior, basic knowledge of PrEP and usage of PrEP. The differences in using PrEP among MSM with different characteristics were compared using chi-square test, and the related factors of using PrEP were analyzed by multivariate logistic regression.Results:A total of 1 201 MSM were enrolled in the study. The subjects were mainly 18-29 years old, accounting for 52.5% (631). For the levels of education, the subjects were main undergraduate and above (77.9%). For the monthly income, the subjects were mainly over 10 000 yuan, accounting for 45.4% (545 subjects). The usage rate of PrEP was 12.9% (155 subjects). Higher possibility of using PrEP related to monthly income of over 10 000 yuan, unprotected anal intercourse in the past 6 months, commercial sexual activity in the past 6 months, HIV testing 4 or more times in the past 12 months and having basic knowledge of PrEP.Conclusions:The proportion of PrEP usage among the MSM population in Beijing was relatively low, and further efforts should be made to strengthen publicity and improve PrEP awareness. At the same time, it is emphasized that when conducting HIV counseling and testing as well as providing HIV pro-exposure prophylaxis related services, high-risk behaviors of service recipients should be identified, and to provide actively PrEP promotion and counseling to improve PrEP usage rate among the applicable population.