Malignant germ cell tumors occur in children and young women in reproductive age, of all the germ cell malignancies, only pure dysgerminomas had a high cure rate prior to 1970. This was due to the exquisite radiosensitivity of these tumors. Multiple-agent chemotherapy has dramatically improved the pmgnosis of patients with malignant ovarian germ cell tumors. Clinicopathological analysis was performed on 21 cases of malignant germ cell tumors of the ovary, 9 cases at the department of Obstetrics & Gynecology, Kyung-pook National University Hospital, 4 cases, at the department of Obstetrics and Gynecology, Dong-guk University Kyungju Hospital and 8 cases, at the department of Obstetrics and Gynecology, Dae-gu Fatima Hospital during the period 10 years from July. 19S8 to June. 1997 The results were summarized as follows: 1. The mean age of the patients was 21.8 years old, ranging from 10 to 61 years old. 2. Main initial symptoms were abdominal distension(33.3%), abdominal mass palpation(33.3%), abdominal pain(28.6%), amenorrhea(4.8%) in order. 3. Histologically, the tumors were classified as immature teratoma(57.1%), dysgerminoma(19%), mixed germ cell tumor(9.5%), endodermal sinus tumor(9.5%), embryonal cell carcinoma(4.8%). 4, According to FIGO classification Stage I was the most prevalent(57.1%) at the time of diagnosis while Stage III was forward in 48.6%, Stage II in 9.5%, and no Stage IV, 5. The 5-year survival rate was 80.4% and three patients have died of malignancy and the other 18 patients live without disease from 11 to 102 months, with a median follow-up of 34.2 months. 6. Prognostic factors of malignant germ cell tumors in this study were the clinical stage, the presence of ascites and the residual tumor mass.