Objective: To study the cause and clinical feature of bloody ascites and to improve thediagnostic level of bloody ascites.Method: 48 patients with bloody ascites from our department were investigated for the cause,clinical feature,laboratory examinations and X-image.Result: Among 48 cases,35 patients(72.9%) had tumor,which was in the top causes for bloody ascites,in which 18 cases were gastroenterological tumor,while 13 patients had not malignant tumor(27.1%).Conclusion: The incidence of bloody ascites is much high in the malignant tumor,especially in gastroenterological tumor.Diagnosis is used by many ways.