Abstract: Objective To investigate the clinical characteristics and prognosis of primary peritoneal carcinoma （PPC）. Methods The clinical characteristics of 18 patients with PPC， who were treated in our hospital from January 2004 to January 2015， were analyzed retrospectively. Results Eighteen patients were women and the average age of morbidity was （64±5） years. There were 12 cases （66.6％） of abdominal distension and ascites， 17 cases （94.4％） without adnexal mass in gynecological examination and 17 cases （94.4％） with elevated CA125. There were 16 cases （88.8％） with peritoneum and／or greater omentum lesions in operation. Fifteen patients with PPC underwent cytoreductive operation， and 3 patients only underwent greater omentum and bilateral adnexectomy. Pathological examination results showed that peritoneum and／or greater omentum lesions were commonly diagnosed as poorly differentiated serous adenocarcinoma arising from mullerian duct. Ovarian microinvasion only occurred in 2 cases. By Kaplan-Meier method， the median survival time of 18 patients was 30.0 months （95％CI： 19.5-56.5）， and the 1-， 2-， 3-， 5-year survival rates of PPC were 87.1％， 65.7％， 42.6％ and 21.3％. Conclusion PPC， taking surgical resection and chemotherapy as main treatment， was easy to get confused with ovarian cancer before operation.