Abstract: Objective: To investigate the histopathologically, diagnostic measure and prognosis of Struma Ovarii (SO). Design and Setting:From Jan.2009 to Jan.2022, the general clinical data, results of laboratory examinations, surgical and histopathological test results of 11 patients, age 25-66 years, mean45.5 years old, with struma ovary in the department of Gynecoloy in The Affiliated Hospital of Jiangnan University, were analyzed retrospectively. Population or Sample：1 Struma Ovarii (SO) cases. Methods: Methods Clinical data of 11 Struma Ovarii (SO) cases were retrospectively studied, analyzed the histopathologically, diagnostic measure and prognosis of (SO). In this study, the procedure followed in line with our hospital customized ethical standards, and with the signing of informed consent in clinical research which obtained a informed consent from the patients. Results: The clinical manifestations of these patients were pelvic mass, bloating, breathing difficulty, peritoneal dropsy, pelvic mass and the CA125 levels may be elevated. Conclusions: Struma Ovarii is a highly specific ovarian teratoma, mostly benign. Struma Ovarii is rare in clinical because its no obvious clinical feature and characteristics preoperative and intraoperative diagnosis was difficult. Its preoperative misdiagnosis rate is high but the malignant transformation rate is very low, prognosis good for most of patients. Intraoperative frozen histopathological examination for early diagnosis can avoid unnecessary surgery to expand. Serial measurement of serum thyroglobulin is a sensitive and cost-effective follow-up tool. A period of at least 10 years is recommended.