Abstract: Objective To evaluate the inter uterine device(IU D)use with risk of endometrial cancer.Methods In a population based case-comtrol study was conducted in urban Shang hai.In-person interv iews were completed for 1 204 incidence cases ag ed 30~69 from January 1997 to December 2002,and 1 212 controls frequency-matched were selected to cases on age.Uncondit ional Log istic regr ession model was applied to drive odds ratios and confidence interv al in association with IU Duse.Results The most frequently used IUD in Shanghai were metallic and V-shaped plastic IU D(68.1% and 20.7%).A significant inverse association was obser ved for IUD use and endometrial cancer r isk.Compared to nonusers,women with a history of IU Duse had a sig nificant reduced risk of endometrial cancer(OR=0.57;95%CI:0.47~0.69)and the ORs decr eased w ith the incr ease of using years.The inverse association did not appear to be modified by menopausal status and oral contraceptive use.Conclusion IUD use is inversely associated with endometrial cancer risk among women in urban shanghai.