Abstract： Objective To observe the immunologic function and effect of lentinan combined with chemotherapy in treatment of gastric carcinoma.Methods Eighty-two cases of gastric carcinoma were randomly divided into observation group(42 cases)and control group(40 cases).The patients in treatment group were treated with lentinan and chemotherapy,and the patients in control group were treated with chemotherapy only.The therapeutic effect,immune functions,Karnofsky performance status(KPS)score,adverse effect in two groups were observed and compared.Results The total effective rate in observation group and control group was 61.9％(26/42)and 40％(18/40),and there was significant difference(P ＜ 0.05).Compared to before treatment,in observation group,CDs reduced,and CD3,CD4,CD4/CD8,nature kill(NK)cell increased,while in control group,CD4/CDs and NK cell reduced,CD3 increased,and there were significant differences(all P ＜ 0.05).There was significant difference in CD3,CD4,CD4/CDs,NK cell activity between observation group and control group (P ＜ 0.05).The rate of KPS score increasing in observation group was higher than that in control group.The rates of blood platelet decreasing and leucopenia in observation group were lower than those in control group. Conclusions Lentinan combined with chemotherapy can enhance some immunological function and clinical effect in patients with gastric carcinoma.So lentinan is an important remedy adjuvant of chemotherapy.