Abstract: Objective To study the effect of hyperinsulinemia（HI） on expression of leukemia inhibition factors（LIF） in endometrial epithelial cells and the effect of insulin resistance（IR） in polycystic ovarian syndrome（PCOS） on the endometrial receptivity. Methods Well-differentiated human endometrial adenocarcinoma cells（Ishikawa cells） were cultured in vitro.Insulin was added to the Ishikawa cells cultured with insulin at different concentrations（10mU/L,30mU/L,and 90mU/L） for 24h.LIF levels in supernatant of cultured Ishikawa cells were measured by ELISA. Results The expression level of LIF was higher in control group than in different insulin treatment groups（F=23.70,P＜0.01）.However,no significance was observed in the expression level of LIF in Ishikawa cells between different groups after treatment with insulin at different concentrations（P＞0.05）. Conclusion The expression level of LIF in supernatant of Ishikawa cells cultured with insulin at different concentrations is low,indicating that the IR may be one of the factors affecting the endometrial receptivity of PCOS,thus leading to the worse outcome in PCOS patients.