Objective. To evaluate the surgery in simple ovarian cysts.Methods. From Jan. 1994 to Dec. 1999, 221 women with simple ovarian cysts were admitted into ourhospital. The diameter of cysts was ＜5 cm in 76 cases, and was≥5 cm in 145 cases ultrasonically.One hundred and eighty-four patients underwent laparosocopy, and thirty-seven underwent laparotomy.Results. Histological findings showed no malignancy in this series. Simple cysts, paraovarian cystsand corpus luteum were found histologically in 90.8% of cases with cysts ＜5 cm, and 60% of those withcysts ＞7 cm respectively, their difference was significant (X2=-37.13, P＜0.001). The simple cysts, paraovar-ian cysts and corpus luteum cysts were found in 81.5% of postmenopausal women and 84.0% of pre-menopausal women. Conclusion. Patients with cysts ＞7 cm are indicated for surgical procedures, while a period of fol-lowup is acceptable for patients with cysts ＜7 cm, and surgery is advisable if the cyst is persistent dur-ing followup. Postmenopausal women with cysts should have operations.