Abstract: OBJECTIVE To observe the impact of Shenmai injection combined with chemotherapy on advanced non-small cell lung cancer patients' immunity and cytokines. METHODS 48 cases were randomly divided into two groups: the combining treatment group and the chemotherapy group. Patients with squamous carcinoma were given Docetaxel and cisplatin chemotherapy; patients with adenocarcinomas and large cell carcinoma were given pemetrexed disodium together with cisplatin chemotherapy. Shenmai injection was added in the combining treatment group. Immune indexes like peripheral T lymphocyte subsets and the viability of NK cells together with peripheral blood cell factor level and short term effects of chemotherapy and the side effects shown were recorded before the chemotherapy and two cycles of treatment. RESULTS After treatment，the level of CD4⁺ and CD4⁺/CD8⁺ in combined treatment group increased significantly(P<0.05~0.01). Compared to the chemotherapy group， the levels of CD3⁺， CD4⁺ and CD4⁺/CD8⁺ of treatment group have significant difference(P<0.01). The expression of IFN-γ， TNF-α， IL-2 in combination group increased significantly(P<0.01). The levels of IFN-γ and IL-2 of treatment group had significant difference(P<0.01) ，compared with the control group. The response rate of these two groups is similar.The incidence of hematologic toxicities in the treatment group was lower than that in control group(P<0.05~0.01). CONCLUSION The combination of Shenmai injection with chemotherapy can improve advanced stage non-small lung cancer patients' immunity and reverse the Th1/Th2 ratio， and reduce the toxicity of chemotherapy.