To disseminate the knowledge of contraception and STD/AIDS prevention to unmarried young adults. A peer-led 8-month intervention on reproductive health promotion and STD/ AIDS prevention was conducted in joint venture factories in Kunshan County through existing family planning service network. A quasi-experimental design was used. The contraception, STD/AIDS related knowledge and attitudes improved significantly, and the use of condom also increased significantly in experimental group after the intervention. No such changes occurred in control group. This study demonstrates that the peer-led education is an effective approach of expanding reproductive health and AIDS prevention services to unmarried young adults in the joint venture factories.