Abstract: Ovarian sclerosing stromal tumor(OSST)is a benign ovarian sex cord stromal tumor. There are about 100 cases reported in literature. OSST usually occurs in women of childbearing age from 20 to 30 years old. The clinical manifestations are abdominal pain and adnexal mass. The tumor may have endocrine function, causing menstrual disorder and infertility, and a few patients even appear masculine. OSST is rare in prepubertal girls. Half of the patients go to see a doctor due to the accidental discovery of pelvic tumors during physical examination or the clinical manifestations caused by the increase of sex hormones. It usually occurs in one side of the ovary. Only 3 cases reported tumors in bilateral ovaries. For young women with bilateral OSST, bilateral ovarian tumor resection or operation with normal ovarian tissue on one side can be performed to preserve the fertility of the patients. In this paper, we report a rare case of bilateral OSST of the ovaries in a premenstrual girl and review the literature.