Abstract: Objective To sum up the experiences of diagnosis and treatment of peritoneal malignant mesothelioma(PMM)and study the clinical characteristics of this disease, in order to improve the recognition of it. Methods Clinical data about 21 cases with pathologically confirmed PMM from January 1995 to January 2015 were retrospectively analyzed.Seventeen of the patients were males, and the other four were females.The main clinical manifestations were abdominal distention and weight loss, while the main sign was ascites. Results The level of serum CA125 was higher than normal in 10 of the 16 examined patients.Ultrasonography or CT revealed peritoneal thickening in 18 cases, which were based on laparoscopy.The main pathological type was epithelial.Postoperatively, abdominal chemotherapy was performed in 13 cases, systemic chemotherapy in 2 cases, cytoreductive surgery in 1 case and cytoreductive surgery+abdominal chemotherapy in 3 cases. Conclusion The final diagnosis depends on pathological finding, laparoscopy combined with surgery should be adopted for the treatment of this disease with life cycle of 3 to 24 months.