To understand the human immunodeficiency virus (HIV) infection status and syphilis prevalence among men who have sex with men (MSM) receiving voluntary counseling and testing appointed through a web-based registering system and related factors. The MSM receiving web appointed HIV counseling and testing from 2011 to 2012 in Guangzhou were recruited and a questionnaire survey was conduct among them to obtain the information about their demographic characteristics and sexual behavior. Binary and multivariate logistic regression model were used to identify the factors associated with HIV infection or syphilis prevalence. A total of 4,904 MSM were enrolled in the study, the average age of the MSM was (28.77±7.24) years, and 70.3% of them had high education level; the unmarried MSM accounted for 72.7%. The HIV infection rate and syphilis prevalence were 8.7% and 4.4% respectively. The co-infection rate of HIV and Treponema pallidum was 1.2% (59/4 904). About one in three MSM did not use condom at latest homosexual behavior, 43.5% did not use condoms at each homosexual behavior in the past three months. Lower education level, occupation (worker or farmer), non-consistent condom use at each sex with men in the past three months, receiving HIV test or not and Treponema pallidum infection were associated with HIV infection. Age≥40 years, lower education level, multi male sex partners in the past three months and HIV infection were associated with Treponema pallidum infection. MSM receiving web appointed HIV counseling and testing had high prevalence of risk behaviors and high HIV infection rate, but had low previous HIV testing rate. It is necessary to strengthen the promotion of HIV test through web based appointment and conduct target behavior intervention in older MSM with lower education level.