Objective To study the correlationship of morphology and immunohistochemistry of uterine serous carcinoma (USC) and its precancerous lesion of endometrial glandular dysplasia (EmGD) in the postmenopausal women. Methods The clinical and pathological manifestations of 14 cases of USC and EmGD were analyzed retrospectively. Immunohistochemical SP method was used to detect the expression of P53 protein, Ki-67 index, estrogen receptor (ER), and progestrone receptor (PR) in the tissues. And 10 cases of normal postmenopausal endometrium were enrolled as control group. Results The clinical and pathological features of USC and EmGD were distinctive. Compared to normal endometrium tissues, the local expression of P53 protein and the Ki-67 index in USC were the highest, meanwhile the local expression of P53 and Ki-67 index in EmGD were between those in USC and in normal endometrium. Conclusion There is significant correlation between EmGD and USC, the former can be regarded as precancerous lesion of USC. In addition to treat the patients with USC comprehensively, we also should take active and effective measures to deal with patients with EmGD to block the occurrence of USC.