Objective: To explore a method for predicting peritoneal metastasis in gastric carcinoma patients. Methods: Peritoneal washings and clinical data of 50 patients with gastric carcinoma and 10 patients with benign gastric diseases were collected. The CEA of peritoneal washings was detected by flow cytometry, the peritoneal lavage cytology(PLC) was examined by HE stain, and the clinical significance of the abovementioned data was analyzed. Results: The positive rate of CEA in peritoneal washings of gastric carcinoma group was 54.0%(27 cases), the positive rate of CEA was significantly higher than the PLC detection rate (24%, 12 cases). The positive rate of CEA increased with the depth of tumor invasion，TNM staging and degree of peritoneum involvement increased. Conclusions: Detection of CEA and other markers in peritoneal washings by flow cytometry can be used to predict peritoneal metastasis of gastric carcinoma.