RESUMEN
Objective To study the prevalence of human immunodeficiency virus(Hiv),sexually transmitted infection(Sti),risk behavior and the sexual neworks among men who have sex with men (MSM)in Taizhou city，Zhejiang province.Methods cross-sectional Astudy was applied with venue-based sampling in 2 MSM gathering sites in Taizhou.'Informed Consent'principle was applied and MSM were studied through a structured questionnaire．Blood samples were collected from thee who accepted free and confidential HIV/STI counseling and then tested for HIV,syphilis,HCV and HsV-2 antibodies with ELISA.HIV positive sera were certified with western blot．Results 106 MSM were investigated and 97 qualified questionnaires were collected.25.0％(23/92)of these MSM have ever had l female sex partner while 47.8％(44/92)had 2 or more.14.3％(13/91)of them reported having had 1 male partner who had engaged in anal sex and 80.2％(73/91)had 2 or more.22.1％(19／86)of therh had partieipated in group sex but 62.5％(55／88)of them did not always use condom when having analintercourse.15.1％(14／93) of them had l orfll sex partner while 75.3％(70／93)having 2 or more.38.9％(37／95)of them had sex with female sex worker,and 35.5％(33／93)had sex with male-to-male sex worker.15.3％(13/85)0f them had once been male-to-male sex worker themselves.3.9％(3/77)of them were found HIV positive in blood tests,with 24.7％(18/73)positive of syphilis,15.1％(11/73)positive ofHSV-2 but HCV appeared to be negative.46 csses reported their egocentric recognition networks,with mean degree of 5.91(ranging0-10),and mesa density of 0.548(ranging 0．000-1.000).43 sexual networks were identified,with mean degree of 2.70(ranging 0-10),and mean density of 0.246(ranging 0.000-1.000).Conclusion Risk behaviors,such as multiple sex partners，IOW proportion of condom use and commercial sex engagement both with heterosexuals and homosexuals,were extensively existed among MSM in Taizhou,and the prevalence of HIV/STI was relatively high.Their sexual networks seemed complicated but there might be in place of some sukstantiaUy isolated MSM groups with high risk of Hlv/sTl infection.More study should be applied to identify the relationship between scxual networks and HIV/STI transmigsion.