目的 评价同伴教育对农村留守中学生性健康的干预效果，探索适合西部农村留守中学生的健康教育模式。方法 多阶段整群随机抽取四川达州3个农村中学，每个中学抽取6个初二班级，再随机分为同伴教育组、传统教育组和对照组。分析干预前后的问卷调查数据以检验短期效果（知识），对同伴教育组和传统教育组干预后6个月再进行随访调查以检验中长期效果（态度和行为）。结果 干预后，同伴教育组的性健康知识总知晓率从49.4%提高到75.3%，知识平均分从（6.77±3.14）分提高到（8.61±2.88）分，差异有统计学意义（P=0.001）。传统教育组的总知晓率从51.0%提高到67.5%，平均分从（6.89±2.91）分提高到（7.41±3.11）分，差异也有统计学意义（P=0.024）。对照组干预前后平均分差异无统计学意义（P>0.05）。同伴教育组干预后即时调查的知识平均分为（8.61±2.88）分，显著高于传统教育组的（7.41±3.11）分（P=0.000），平均分差异为1.19分（95%CI为0.58~1.81）。6个月后随访调查显示，与干预前比较，同伴教育组和传统教育组均正性态度率提高、负面行为率降低（P<0.05）；且同伴教育组效果优于传统教育组（P<0.05）。结论 针对农村留守中学生开展性健康干预取得了明显效果，同伴教育方法更适合留守农村中学生的性健康教育，健康态度和行为的长期变化需要进一步研究。

Objective To evaluate the intervention effect of peer-led education on the sexual health of rural left-behind middle school students and explore the health education mode suitable for rural left-behind students in West China. Methods Three rural schools in Dazhou, Sichuan province were sampled by the multi-stage cluster random sampling method. Six second grade classes of each school were selected and randomly divided into the peer-led education group, traditional education group, and control group. Data of questionnaire surveys before and after the intervention were analyzed to evaluate the short term effect (knowledge). Follow-up surveys of the peer-led education group and traditional education group were conducted after being intervened for six months to evaluate the medium and longterm effect (attitude and behavior). Results The awareness rate of sexual health knowledge of the peer-led education group increased from 49.4% to 75.3% and the average sore increased from 6.77±3.14 to 8.61±2.88 after being intervened. The differences were statistically significant (P=0.001). The awareness rate of sexual health knowledge of the traditional education group increased from 51.0% to 67.5% and the average sore increased from 6.89±2.91 to 7.41±3.11 after being intervened. The differences were statistically significant (P=0.024). The difference of the average sores of the control group before and after intervention was not statistically significant (P>0.05). The average sore of the peer-led education group immediately after intervention was 8.61±2.88, which was significantly higher than 7.41±3.11 of the traditional education group (P=0.000). The difference of the average sore was 1.19 (95%CI was 0.58-1.81). Follow-up surveys after six months showed that rates of positive attitude of the peer-led education group and traditional education group increased and rates of negative behavior decreased compared to those before intervention (P<0.05). The results of the peer-led education group were better than those of the traditional education group (P<0.05). Conclusion Sexual health education for rural left-behind middle school students is effective. The peer-led education method is more suitable. Changes of health attitude and behavior still need further study.