Abstract: Objective To observe the expression of DR5 and DcR2 in the endometrium of polycystic ovary syndrome (PCOS)rats and explore other possible mechanisms of the dysfunction of endometrium in PCOS. Methods Rats were subcutaneously injected with sodium proprteone sulfate to construct the PCOS model. The expression of DR5 and DcR2 in the uterus of PCOS and control rats was compared by immunohistochemistry and western blot respectively. Results Immunohistochemistry assay showed that DR5 and DcR2 were mainly expressed in the endometrium epithelial cells. The relative expression of DR5 in endometrial glandular epithelial cells of PCOS group and control group were 0.083±0.004 and 0.161±0.002 respectively, with statistically significant difference (P=0.000). The relative expression of DcR2 in the endometrial glandular epithelial cells of the two groups were 0.061±0.003 and 0.062±0.002 (P=0.720). Western blot assay showed that the relative expression of DR5 in the uterus of PCOS group and control group were 0.997±0.021 and 1.282±0.015 respectively, and the difference was statistically significant (P=0.000).The relative expression of DcR2 in the uterus of PCOS group and control group were 0.906±0.078 and 0.860±0.064, respectively, without significant difference (P=0.474). Conclusion The dysfunction of endometrial function in PCOS may be related to the downregulation of DR5 expression in the endometrium.