Disease analysis: Chocolate cyst of ovary is a pathological change of endometriosis, belonging to metabolic disease, regardless of age. Chocolate cyst is formed by endometriosis on the ovary. This kind of cyst can gradually increase, and sometimes it will rupture during or after menstruation, but it rarely becomes malignant. Suggestions: Burst cysts can cause severe abdominal pain, nausea and vomiting, and often need emergency treatment. Cyst rupture mostly occurs in premenstrual period and menstrual period. Ovarian chocolate cyst rupture is a new type of acute abdomen in gynecological field. In the past, it was often ignored because of insufficient understanding, but now it has been gradually deepened, so it has attracted attention.