Objective To investigate the characteristics of magnetic resonance imaging (MRI) in the diagnosis of ovarian cystadenoma and to improve the ability of diagnosis and differential diagnosis, and to provide accurate guidance for clinical preoperative evaluation. Methods MRI findings of 38 cases of ovarian cystadenoma confirmed by operation and pathology were analyzed retrospectively, including MRI conventional imaging, Diffusion weighted imaging (DWI) and dynamically enhanced imaging features. Results There were 50 lesions in 38 cases, 16 cases were serous cystadenoma with 23 lesions, 22 cases were mucinous cystadenoma with 27 lesions. The benign manifestations were thin and smooth wall, and thin and regular septa, T1WI showed low and equal signal, T2WI showed high signal, DWI showed high or low signal, the signal is uniform, with no enhancement. Borderline or malignant manifestation of cystic solid mixed signal, cyst wall and capsule separated thick and irregular, see the cyst wall nodules were papillary or irregular, DWI was high or mixed signal, enhanced scan see separation and wall junction Section enhancement. And compared with pathological results, 8casas of diagnosis error, 1 case of mucinous cystadenoma misdiagnosed as simple cysts, 1 case of mixed mucinous cystadenoma misdiagnosed as teratoma, 6 case of borderline without prompt including 3 cases of serous (including 1 cases of malignant transformation), 3 cases of mucinous. The diagnostic rate of cystadenoma was 94.7%(36/38), the coincidence rate of benign and malignant diagnosis was 84.2%(32/38). Conclusion MRI imaging can show the morphological and signal characteristics of ovarian cystadenoma, especially DWI and enhanced scan of ovarian cystadenoma have a great advantage in the qualitative and differential diagnosis, and providing adequate imaging basis for clinical treatment.