Abstract: Objective： To evaluate the relationship between oral contraceptives（OC） and the risk of uterine leiomyomata（UL） among fertile women. Methods： A case?鄄control study was carried out， to investigate 513 UL cases and the matched controls by the unified questionnaire and health examination tables. Logistic regression was used to analyze risk factors of UL. Results： Comparison with OC never-using women， OC current-using women had the significantly increased risk of UL（adjusted OR=1.80， 95% CI： 1.19~2.71）， OC former-using women had the increased risk of UL（adjusted OR=1.27，95% CI： 0.95-1.70）. Multivariate logistic regression analysis showed that the main risk factors of UL included OC current-using（OR=1.73，95% CI：1.13~2.65） and body mass index（BMI） more than 25 kg/m2（OR=1.35，95% CI：1.02~1.78）. Conclusions： The risk of UL slightly increased among reproductive-age-women with BMI≥25 kg/m2 and OC current-using. Other potential risk factors need to be evaluated in further studies.

Key words: Contraceptives, oral, Uterine neoplasms, Leiomyoma, Case-control studies, Risk factors