Abstract： Objective To investigate the possible association between insulin resistance and endometrial cancer.Methods   Forty cases (case group) with newly diagnosed endometrial cancer and 48 healthy women(control group) from health examination at the same period were enrolled in this study.Fasting blood glucose(FBG）, fasting serum insulin (FINS), estradiol (E2), luteinizing hormone (LH), follicle stimulating hormone (FSH) and prolactin( PRL)were measured in all patients. Results  The levels of FINS, HOMA-IR, E2 and FSH of the case group were significantly higher than those of control group (P<0.05).No significant correlation was observed between case group and normal control in tumor type , grade, the depth of myometrial invasion, estradiol receptor or progesterone receptor(P>0.05).FINS related to endometrial cancer was not influenced after adjusting other confounders in this study. Conclusions  FINS may be an independent risk factor in developing endometrial cancer, which has dose-response relationship,and is positively related to E2,and inversely correlated with FSH.The affect of insulin  on the sex hormone might be one of the mechanisms of endometrial carcinoma.