Objective:To study regulation of external leukemia inhibitory factor(LIF) and interlukin 1(IL 1) on the expression of integrin β 3 in the mouse endometrium during peri implantation period and explore the mechanism which LIF participate in embryonic implantation.Methods:The mice were injected peritoneally with LIF,IL 1 or IL 1ra at different administration on day 2~4 of pregnancy.The level of integrin β 3 protein was measured with Westernblot method and mRNA measured with RT PCR.Results:The levels of integrin β 3 protein and mRNA were increased by LIF and IL 1(P<0.05) and which relied on administration.The level of integrin β 3 mRNA was decreased by IL 1ra (P<0.05).Conclusion:LIF and IL 1 of cytokines can improve the expression of integrin β 3 in the peri implantation endometrium of mouse.Both of them may take part in implantation by regulating cell adhesion molecules.