Ovarian cancer is a common gynecologic malignancy, and it is the gynecologic tumor with the worst prognosis. The five-year survival rate for early-stage ovarian cancer can reach 90%, but for advanced cases, even with intensive treatment, the five-year survival rate is still only 30-40%. One of the major reasons for the poor prognosis of ovarian cancer is that it develops insidiously and is often diagnosed at an advanced stage. Ovarian cancer usually has no obvious discomfort in the early stage, but only in the late stage will there be obvious symptoms, including: abdominal (gastrointestinal) discomfort, belching, indigestion, bloating or pain; nausea, vomiting, diarrhea, constipation, frequent urination; poor appetite; bloating even with little food; unexplained weight gain or loss; and abnormal vaginal bleeding. These symptoms can be caused by ovarian cancer or other diseases, but it is important to have these symptoms checked by a doctor as soon as they are detected. We often encounter patients who have been misdiagnosed with ovarian cancer for various reasons, including patients who came to the clinic from the gastroenterology department for treatment of “liver cirrhosis” for a long time, or patients who were diagnosed with benign ovarian cysts, which delayed the best time for treatment. Clinically, the diseases that often need to be differentiated from ovarian cancer are: 1. Pelvic endometriosis: the symptoms of this disease are very similar to those of ovarian cancer, such as the formation of adherent ovarian masses and rectal sunken nodules, but this disease is often identified in patients of reproductive age, with progressive dysmenorrhea, aggravated by menstrual cycle and infertility. If necessary, abdominal or cesarean exploration is performed to confirm the diagnosis. 2, adnexal tuberculosis or peritoneal tuberculosis: there is often a history of tuberculosis, and its clinical manifestations are different. Adnexal tuberculosis has symptoms such as wasting, low fever, night sweats, flushing, postmenstrual error and thinning, amenorrhea. In peritoneal tuberculosis ascites appears as an adherent mass, characterized by high location. Ultrasound and X-ray gastroenterography can help to confirm the diagnosis and facilitate identification. 3. Pelvic inflammatory mass: Inflammation can form a substantial, uneven and fixed mass, or parametritis with inflammatory infiltration reaching the pelvic wall similar to ovarian cancer symptoms. Patients with pelvic inflammatory masses often have a history of abortion, IUD, IUD removal, postpartum infection, etc. Pelvic inflammatory disease is mainly characterized by clinical manifestations such as fever, lower abdominal pain, long duration of the disease, and obvious tenderness on bimanual examination, and the mass shrinks with the application of anti-inflammatory treatment. When necessary, cytological examination of the mass should be performed. 4, cirrhosis ascites: according to the performance of cirrhosis symptoms, liver function test results, pelvic examination with or without masses, ascites properties, etc. It is not difficult to identify, if necessary, B ultrasound, CT and other auxiliary examinations. 5, benign ovarian tumors: benign tumors have a relatively long course, the masses gradually increase in size, often occur unilaterally, with good mobility, soft texture, smooth surface, intact envelope and no defects, these tumors are more common and patients are generally in good condition. On the contrary, ovarian malignant tumor has a short course and the mass grows faster, with poor mobility, hard texture and unsmooth surface. If necessary, laparoscopy and abdominal dissection can be performed to further clarify the diagnosis.