Abstract: In order to understand the effects of Lentinan，235 cases of advanced gastric cancer or postoperative radical gastrectomy received both lentinan and chemotherapy comparing with 84 control cases who were only administrated chemotherapy were studied。The results showed that lentinan，as an adjuvant drug to chemotherapy，can obviously enhance the immunity and improve life quality of the patients，as well as increase the complete response rate(study group 30.5% vs·control group 14.8%and decrease side effects of chemotherapy.