Malignant peritoneal mesothelioma originates from the epithelial ormesenchymal tissue of the peritoneal cavity. It is a rare malignancy without specific clinical symptoms, sensitive laboratory examination and typical imaging features. The early diagnosis of malignant peritoneal mesothelioma is difficult and the mortality is high. The final diagnosis depends on pathology and immunohistological examination. For the time being there is not yet a definite treatment strategy. Most cases are diagnosed at late stage and its prognosis is poor. Here we reported one rare case to draw the attention of physicians through rough discussion and literature review: A 54-years old man, initially misdiagnosed as colon cancer combined ascites. The final diagnosis depended on laparotomy exploration and biopsy by laparoscope. Ascites was unable to control after local abdominal cavity chemotherapeutic instillation with many kinds of drugs and the total amount of ascites was more than 70 000 mL. The overall survival was 15 months.