〔Abstract〕 Objective To analyze the clinical characteristics of patients with adenomyosis(AM) and endometrial cancer(EC) and their role in preoperative diagnosis. Methods A total of 142 patients with AM complicated with EC or endometrial atypical hyperplasia(EAH) and AM with abnormal uterine bleeding(AUB) during the same period were collected from this hospital. They were divided into AM with EC or EAH group(71 cases) and control group(71 cases) according to whether they were complicated with EC or EAH. The clinical data of the patients were retrospectively analyzed, and the clinical characteristics and treatment strategies of the patients with adenomyosis complicated with endometrial cancer were discussed.Results Univariate analysis showed that age, increased proportion of CA125 and CA125, uterine volume, proportion of hypertension and abnormal endometrial ultrasonography in patients with AM with EC or EAH were significantly higher than those in the control group, and the proportion of dysmenorrhea was significantly lower than that in the control group, and the difference was statistically significant(P<0. 05). Multivariate Logistic regression analysis showed that endometrial thickening, endometrial echogenicity, and endometrial thickening combined with echogenicity were independent risk factors for AM with EC or EAH.Conclusion In clinical practice, the patients with AM with endometrial thickening or uneven echo-echo of ultrasound should be treated by hysteroscopy and curettage before further operation plan is formulated, so as to achieve the purpose of early diagnosis and treatment of EC.