Abstract: To study the effect of different level of sex steroids on the proliferation and differentiation of endometrial cells, rabbit endometrial epithelial cells and stromal cells were isolated using centrifugation method. The different level and combination of progesterone (P4) and βestradiol (E2) were added in media, the proliferative capability of the cells in vitro was determined indirectly by MTT method. The specificity and homogeneity of the epithelial cells and stromal cell cultured in media containing sex steroids were determined by immunocytochemistry employing antibodies against cytokeratin and vimentin respectively. The results stated that high purity epithelial cells and stromal cells were isolated using centrifugation method. 100 nmol/L P4 in media can stimulate the proliferation of stroma cell, thus a combination of 100 nmol/L E2 and 10 nmol/L P4 in media can stimulate the proliferation of epithelial cell (P<0.05). Immunocytochemistry staining demonstrated that cytokeratin was positive in epithelial cells and vimentin was detectable in stromal cells. This study demonstrated that sex steroids can promote proliferation of endometrial cells in vitro and maintain its specificity and homogeneity.