目的 了解上海市外来未婚女工艾滋病相关知识、态度和婚前性行为现状，并探讨婚前性行为的影响因素。方法 采用整群随机抽样方法，选择上海市3家工厂的800

名外来未婚女性务工人员进行问卷调查，回收769份，回收率为96.1%；有效问卷762份，有效率为99.1%。问卷内容主要包括人口学基本信息以及艾滋病相关知识、态度和婚前性行为。采用多因素Logistic回归分析婚前性行为的影响因素。结果 艾滋病相关知识的应答正确率为56.4%，对婚前性行为持反对态度的占38.1%，有36.1%的调查对象承认发生过婚前性行为。多因素Logistic回归分析显示婚前性行为发生的影响因素包括年龄（>25岁组与<20岁组比较：OR=2.16，95%CI=1.12~4.17）、居住状况（租房组与集体寝室组比较：OR=3.67，95%CI=2.03~6.63）、家乡（东部地区组与中西部地区组比较：OR=3.13，95%CI=1.64~5.97）和婚前性行为态度（赞同组与反对组比较：OR=9.23，95%CI=4.90~17.39；中立组与反对组比较：OR=3.85，95%CI=2.16~6.86）。结论 上海市外来未婚女工的艾滋病知识相对薄弱，婚前性行为态度较为开放，婚前性行为发生率较高，有必要加强安全性行为的健康促进，减少艾滋病及其他性传播疾病感染和意外妊娠的风险。

Objective To assess the HIV/AIDS related knowledge, attitude, prevalence of premarital sexual intercourse among unmarried female migrant workers in Shanghai, and to explore factors associated with premarital intercourse. Methods A total of 800 unmarried female migrant workers from three factories were recruited using cluster random sampling. The response rate was 96.1% (769 replies) and 762 (99.1%) were usable questionnaires.  The questionnaire contents were emographic characteristics, HIV/AIDS related knowledge, attitude, and prevalence of premarital sexual intercourse. Logistic regression was used to examine the correlation between premarital sexual intercourse and risk factors. Results The overall correct answer rate of HIV/AIDS related knowledge was 56.4%; the participants against premarital sexual intercourse were 38.1%; and the prevalence of premarital sexual intercourse was 36.1%. Multiple-logistic regression analysis shower that premarital sexual intercourse was associated with four factors: ①age (>25 years group vs <20 years group: OR=2.16, 95%CI=1.12-4.17), ②current residence (rental vs dormitory: OR=3.67, 95%CI=2.03-6.63), ③hometown (east vs mid-west: OR=3.13, 95%CI=1.64-5.97), ④attitude to premarital sexual intercourse (agree vs disagree: OR=9.23, 95%CI=4.90-17.39; neutrality vs disagree: OR=3.85, 95%CI=2.16-6.86). Conclusion Unmarried female migrant workers in Shanghai relatively lack of HIV/AIDS related knowledge, but they have open attitude toward premarital sexual intercourse so the prevalence of premarital sexual intercourse is high. It is necessary to conduct safe sex promotions to reduce the risk of HIV/AIDS, other sexual transmitted infections, and unintended pregnancy.