Abstract: Objective To identify the epidemic character istics and HIV transmission in HIV discordant couples.Methods HIV/AIDS database down loaded from HIV website system was used for analysis.HIV/AIDS discordant couples confirmed before 2009 were selected.Information on soc iodemog raphic character istics, risk behavior, history of sexually transmitted disease, condomuse, incidence rate and risk factors of HIV infection among the couples were collected and analyzed.Results A total of 843 ouples were enrolled in the study.Among the participants with HIV/AIDS, 61.7% were male; 78% were with education under senior high school and 57.1% were local residents.The major risk behavior was extramarital sexbehavior(75.4%).The condom use rates were 28.4%, 94.5% at the time of first and last followup.Thirteen couples were turned to HIV positive with a sero incidence rate of 0.74 per 100 person year.The risk factor of HIV infection in the couples was with spouse of AIDS and the protective factors included times of followup and continuous condomuse.Conclusion HIV discordant couples had high risk of HIV transmission between the spouses.Having HIV test timely and improving intervention might prevent the HIV transmission between discordant couples.