Abstract: Objective To examine the status of sexual behavior and sexually transmitted infection(STI)related knowledge among lesbians in Liaocheng city of Shandong province. Methods A face-to-face interview was conducted with a self-designed questionnaire in Liaocheng city between 2013 and 2015 among 163 lesbians recruited via internet or at public places with snow-ball sampling. Results Of the lesbians interviewed, 68.1% were aged 20-30 years;71.8% were unmarried;75.5% reported sexual behavior before the age of 20 years;and 65.6% reported heterosexual experience.Among the lesbians, 21.4% had at least two homosexual partners during the recent six months;11.6% had casual homosexual behavior;13.5% had instrumental sex;8.0% had commercial sex;and 20.3% had homosexual behavior during menstruation.There were 8.1% of the lesbians reporting the experience of sharing sexual instrument during homosexual acts and 76.5% of the lesbians using shared sexual instruments without cleaning.The awareness rate of STI related knowledge was low among the lesbians and 41.6% of the lesbians considered possible STI and reproductive tract infection related to homosexual acts. Conclusion The lesbians are at high risk of reproductive system diseases due to multiple homosexual partners and limited knowledge on healthy and safe homosexual behaviors.