Abstract: Pregnancy combined with malignant ovarian tumor is extremely rare. It's easy to diagnosis by imaging examinations and serum markers. The treatment of the patients with malignant ovarian tumor who want to keep on gestation needs follow-up strictly in the first trimester， included imaging examinations and serum markers. Biopsy，a simple staging surgery，chemotherapy is managed in the second trimester. Cesarean section and comprehensive staging surgery are operated in third trimester，and postoperative chemotherapy needs be given completely. Pregnancy promotes growth and metastasis of tumor. Therapy and growth of tumor cause miscarriage，premature delivery，fetal distress， fetal growth retardation and so on.

Key words: Pregnancy, Ovarian neoplasms, Diagnosis, Therapy, Neoplasm metastasis