Abstract: Objective: To analyze CT features of ovarian thecoma to enhance the understanding and the correct diagnosis of that disease.Methods: A retrospective analysis of clinical data and CT manifestations is performed in 12 cases of ovarian thecoma sufferers which have been confirmed through surgery and pathology.CT manifestations are analyzed in terms of the location,size,shape and boundary,plain scan density and intensity extent,whether or not focus of infection having cystic change and ascites.The characteristic of density is subject to myometrium for reference.Results: A total of 12 patients ranging from 23 to 66 years old with a mean age of 38 are enrolled in the clinical study.Of the 12 patients,two suffer from amalgamative uterine myoma,one suffer from amalgamative uterine gland muscle disease,one suffer from amalgamative cervical carcinoma.The tumors of the 12 cases are all unilateral,the shape of most tumors are predominantly round or orbicular-ovate.The small tumors are 1.5cm×2.0cm and the big ones are 5.5cm×7.0cm,average 2.8cm×3.0cm.CT plain scan demonstrates the solid mass in seven cases,cystic-solid mass in four cases,and cystic mass in one case.No ascites is observed in eight cases and mininal ascites in four cases.CT enhancement showed the solid part of tumor with unobvious enhancement at the arterial phase,and inhomogeneous mild enhancement is chief manifestation at the equilibrium phase.The enhancement of cystic part is not observed.Conclusion: The benign morphological characteristic of ovarian thecoma on CT,especially the mild contrast enhancement of its slight blood supply is conducive to the diagnosis and differential diagnosis of the tumor.