Malignant germ cell tumore occur in children and young women in reproductive age, of all the germ cell maligaanci orily pure dysgerminiomas had a high cure rate prior to 1970. This was due to the exquisite wdioseneitivity of these tumors. Multiple agent chemotherapy has dramatieally improved the pr nosis af patients with malignant ovarian germ cell tumors. The purpose of this study is to report the experience at Aaan Medical Center, department of Obstetrics and Gynecology, in 16 patients withmalignant ovarian germ cell tumors treated between July, l989 and June, l994. We analyzed the effect of age, histolagic subtype, FIGO stage, surgical pmcedurse and regimens of chemotherapy, on the prognosis of thwe tumors. The results obtained were as follows: 1. In histologic subtypes, dysgenninoma(38.0%), endodermal sinus tumor(25.0%), squamous cell carcinoma arising in mature cystic teratoma(19.0%), mixed cell tumor(6.0%), immature teratoma(6.0%), malignant ectodermal tumor in mature cystic teratoma(6.0%), were counted in order. 2. No site predilection was identifed. 3. Main initial symptoms were abdominal distension(31.0%), abdominal pain(31.0%), abdominal mass palpation(25.0%), amenorrhea(6.0%) in order. 4. Multiple tumor markers were considered to be useful in diagnosis and follow up of malignant germ cell tumors of ovary. 5. The mean age of malignant ovarian germ cell tumors was 29.5 years, and 11 cases(69.3%) of tumors under the age of 30.0 years. 6. The survival rate seemed to be decreased with advancing FIGO stage.