【Abstract】 Objective To analyze the ultrasonographic features of different pathological types of endometrial lesions and explore the key points and misunderstandings in the diagnosis and differential diagnosis of endometrial lesions by transvaginal ultrasound. Methods 591 patients with pathological diagnosis of endometrial lesions in West China Second Hospital of Sichuan University from 2017 to 2018 were selected for retrospective analysis, including 460 cases of endometrial polyps (endometrial polyps group) and 61 cases of endometrial hyperplasia (endometrial hyperplasia group), There were 42 cases of endometrial hyperplasia with endometrial polyps (endometrial hyperplasia with endometrial polyps group) and 28 cases of endometrial cancer (endometrial cancer group). To analyze the ultrasonographic manifestations of various pathological types of endometrial lesions, and compare the ultrasonographic manifestations of different pathological types of endometrial lesions. Results The incidence of inhomogeneous endometrium in endometrial hyperplasia group was higher than that in endometrial polyps and endometrial cancer group (P＜0.05). The detection rate of slight hyperecho lesions in the endometrium in endometrial polyp group and endometrial cancer group was significantly higher than that in endometrial hyperplasia group (P＜0.05). The detection rate of multiple small endometrial cysts in endometrial hyperplasia group and endometrial polyps with hyperplasia group was higher than that in endometrial polyps group and endometrial cancer group (P＜0.05). The incidence of endometrial blood flow signal changes in endometrial carcinoma group was higher than that in endometrial polyp group and endometrial hyperplasia group (P＜0.05).Comparing the distribution of age of onset, the endometrial polyps group was the youngest, and the endometrial cancer group was the oldest (P＜0.05).Endometrial hyperplasia group was more likely to be associated with adenomyosis and adnexal mass than endometrial polyps group (P＜0.05). Conclusion The slight hyperecho lesions, multiple small cysts in the endometrium, thickness of endometrium, the presence or absence of adenomyosis and adnexal mass, changes in endometrial blood flow signal and the age of patients can be used as important reference indexes in the ultrasonic diagnosis and differential diagnosis of different types of endometrial lesions, so as to improve the efficiency of disease diagnosis.