Objective To discuss the effect of intra-operative and post-operative hyperthermic intraperitoneal lavage chemotherapy for Ⅲb and IV gastric cancer on post-operative peritoneal metastasis and survival rate.Methods The clinical data of 31 cases of gastric cancer(control group)who underwent operation only and 50 cases(chemotherapy group)who receved operation combined with intra-operative and post-operative hyperthermic intra-peritoneal lavage chemotherapy were comparatively studied.Results The survival rate of control group after 2 years and 3 years was lower than that of the chemotherapy group,and the intraperitoneal recurrence raue of cootrol group after 2 years and 3 years was higher than that of chemotherapy group.Conclusions Intra-operative and post-operative hyperthermic intraperitoneal lavage chemotherapy for gastric cancer has important significance in prevention and treatment of peritoneal metastasis and can improve survival rate.