Abstract: Objective To study the effect of soyisoflav on on cell apoptosis and Bcl-2 mRNA expression in the vagina of ovariectomy rats.Methods Fifty adult female Wistar rats were divided into 5 groups:sham-operated group,model group,estradiol group,high soy isoflavone group and soy isoflavone group.TURNEL staining and in situ hybridization with miage analysis system were applied to detect vaginal epithelial cell apoptosis and Bcl-2 mRNA.Results The number of apoptotic vaginal epithelial cells in rats of estradiol and high,low dose soy isoflavone group significantly reduced(P<0.01),and the Bcl-2 mRNA average gray value increased(P<0.05).Compared with the estradiol group,the number of apoptic cells in high and low dose soy isoflavones was significantly higher(P<0.05),while the Bcl-2 mRNA was not different between the estradiol group and the soy isoflavone groups.Conclusion Soy isoflavones may inhibit the apoptosis of vaginal epithelial cells through increased expression of Bcl-2 mRNA.