Ovarian malignant tumor is a common tumor in female reproductive system and one of the three common malignant tumors in women. Ovaries are located deep in the pelvic cavity and early lesions are not easily detected. Once symptoms appear, they are often advanced and manifest as abdominal distension, abdominal masses and cachexia, wasting, severe anemia and other signs of cachexia, which should be highly alerted. In the past 20 years, due to the application of effective chemotherapy regimens, the mortality rate of ovarian malignant germ cell tumors has decreased from 90% to 10%, but the treatment effect of ovarian malignant epithelial tumors has not been improved, and the 5-year survival rate hovers at 30%-40%. With the progress in diagnosis and treatment of cervical cancer and endometrial cancer, ovarian cancer has become a serious life-threatening tumor for women. The etiology of ovarian cancer is still unclear, but environmental and endocrine influences are most valued among the causative factors of ovarian cancer, in addition to regional, racial and familial, marital, and dietary habits. High risk factors for ovarian cancer include: older age, not having had children, having had endometrial cancer, colon cancer, breast cancer; and having a family history of ovarian cancer. The lifetime risk of ovarian cancer for women without a family history of ovarian cancer is 1.4%, with one first-degree relative the risk reaches 5% and with two or more first-degree relatives the risk increases to 7%. About 5-10% of ovarian epithelial cancers have genetic abnormalities. Ovarian tumors can be benign, benign-malignant junction or malignant tumors, and their pathological patterns are diverse. According to the histogenesis of ovaries, they can be classified into epithelial tumors, mesenchymal tumors of the sex cords, germ cell tumors, etc. Among them, epithelial ovarian cancer accounts for 85%-90% of all ovarian malignant tumors. Epithelial carcinoma mostly occurs in older women, accounting for 95% of women over 40 years of age. Germ cell tumors occur mostly in women under the age of 44, asexual cell tumors in young people and young girls under the age of 20, and various types of hypofractionated cancers in older women. Ovarian cancer has no obvious symptoms in the early stage, and with the progress of the disease, some non-specific symptoms often appear, some of which are discovered by chance during gynecological examination; when the tumor increases to medium size, it often feels bloated or a lump is found in the abdomen, and when it gradually increases, abdominal distension appears, and when the tumor fills the pelvic and abdominal cavities, compression symptoms appear, such as frequent urination and constipation, infiltration of surrounding tissues or compression of nerves cause abdominal pain, lumbago and pain in the lower limbs; compression of pelvic cavity and veins cause swelling in the lower limbs. Functional tumors may cause symptoms of androgen or estrogen excess. Premenopausal women may also complain of irregular menstruation or heavy menstruation, and postmenopausal women may also have small amount of vaginal bleeding. Although ovarian tumors have no specific symptoms and are often detected during physical examination, they can be initially identified as ovarian tumors and estimated as benign or malignant based on the patient’s age, medical history and local signs and other characteristics. The physical examination of ovarian malignant tumor is characterized by bilateral, solid or semi-solid, uneven and fixed surface, often accompanied by ascites and nodules in the rectal fossa of the uterus. Ultrasound and CT/MRI can determine the size, shape and nature of the mass site, which can both localize the origin of the mass, whether it is from the ovary, and indicate the nature of the tumor, cystic or solid, benign or malignant, and identify ascites or tuberculous encapsulated fluid of ovarian tumor, which can help the diagnosis. 80% of patients with ovarian epithelial carcinoma AFP test has specific value for endodermal sinus tumor and can assist in the diagnosis of immature teratoma and mixed asexual cell tumor with yolk sac component. HCG test has specificity for primary ovarian choriocarcinoma. When pre-surgical diagnosis is difficult, laparoscopic examination can be performed to directly observe the condition of the mass, and histological examination can be performed on the suspicious points to extract ascites or peritoneal washings to find cancer cells. The treatment goal of ovarian cancer is to fight for cure in early stage; control recurrence in late stage and prolong the survival period. The main treatment modality is surgery plus standard combination chemotherapy. For young patients who desire reproductive function, the scope of surgery is decided according to pathological type and tumor stage, etc. The qualification of the treating physician should be emphasized, and it is best to have ovarian cancer treatment performed by a formally trained gynecologic oncologist. Chemotherapy is an important treatment measure for advanced ovarian cancer and must be timely, adequate and standardized. Ovarian cancer is prone to recurrence and should be followed up and monitored for a long time. The contents of follow-up and monitoring are as follows: 1. clinical symptoms, signs, general and pelvic examinations, emphasizing the importance of each follow-up pelvic examination; 2. tumor markers CA125, AFP, HCG; 3. imaging ultrasound, CT and MRI (if available); 4. positron emission tomography (PET) (if available); 5. steroid hormone measurements: estrogen, progesterone and androgens (for certain tumors); 6. Postoperative follow-up: 1 year after surgery, once a month; 2 years after surgery, once every 3 months; 3 years after surgery, once every 6 months; more than 3 years, once a year. Prevention of ovarian cancer: 1.Strengthen high protein diet rich in vitamin A, avoid high cholesterol diet, take oral contraceptive pills for prevention; 2.Conduct census and general treatment: once a year at age 30, once every six months for high-risk groups; 3.Treat early detection and timely treatment: laparoscopy and dissection as early as possible for pelvic masses with unclear diagnosis or ineffective treatment; 4.Regular follow-up for breast cancer and gastrointestinal cancer patients, oral contraceptive pills before puberty, menopause The ovarian enlargement should be considered as ovarian tumor when found in pre-pubertal, post-menopausal, or oral contraceptive patients of childbearing age.