摘要Objective The ultrastructure of endometrium women suffering from endometriosis was compared with those from women of normal reproductive age.Materials & Methods Six specimens of eutopic endometrium were taken from women diagnosed with endometriosis. Three specimens were taken from women at normal reproductive-age. The specimens, all at early proliferative phase, were processed for ultrastructural study.Results Compared with the normal, the secretory cells of the epithelium of endometrium from women with endometriosis had more numerous and longer microvil li. In the cytoplasm, there were more secretory granules and mitochondria. The RER was more prominent and with dilated cisternae. Lipid droplets and electron dense particles were frequently seen. The cilia ciliated cells were increased and elongated remarkably. The basement membrane became markedly tortouas.Conclusion The endometrium from women with endometriosis showed a number of features which are abnormal. This might be the origin of endometriosis and a cause o f sterility.