Objective: To analyze the pathological classification of malignant peritoneal mesothelioma (MPeM) and screen the immunohistochemical markers that can distinguish MPeM from peritoneal metastatic carcinoma (PC) . Methods: In June 2020, the pathological results of peritoneal biopsy of 158 MPeM and 138 PC patients from Cangzhou Central Hospital, Cangzhou People's Hospital, and Cangzhou Hospital of Integrated Traditional Chinese and Western Medicine from May 2011 to July 2019 were retrospectively analyzed, and the pathological classifications of MPeM in Cangzhou were summarized. Immunohistochemical markers of MPeM and PC patients were analyzed, and receiver operating characteristic curve (ROC curve) was drawn for differential diagnosis of MPeM and PC. Results: There were 55 male and 103 female MPeM patients in Cangzhou, with an average age of 57.1 years old. The asbestos exposure rate was 91.14% (144/158). The most common pathological classifications were cutaneous type, accounting for 90.51% (143/158). There were significant differences in the expression of calreticulum protein, CK5/6, vimentin, D2-40, carcinoembryonic antigen (CEA) and tail type homologous nuclear gene transcription factor 2 (CDX-2) between MPeM and PC (P<0.05). Among the 6 positive markers, the sensitivity of calreticulum protein was the highest (0.905) and CEA was the lowest (0.428) . Conclusion: Calreticulum protein, CK5/6, vimentin, D2-40, CEA and CDX-2 may be used as specific markers to distinguish the diagnosis of MPeM from PC.