Objective: To observe and compare the effect of traditional Chinese medicine (TCM) combined with chemotherapy (CT) on immune function and quality of life (QOL)of patients with non-small cell lung cancer (NSCLC) in stage Ⅲ-Ⅳ. Methods: One hundred cases with stage Ⅲ-Ⅳ NSCLC were randomly divided into two groups. The treated group (n=50) received CT combined with TCM, and the control group received CT alone. The percentage of T lymphocyte subset in peripheral blood and the change of natural killer (NK) cell count were observed after treatment. The QOL and tolerance of CT were also compared between the two groups after treatment. Results: In the treated group, CD3 cell count, CD4 cell count, CD4/CD8 ratio and NK cell activity were higher than those in control group, while CD8 cell count in the treated group was lower than that in the control group (P＜0.05), and QOL and tolerance of CT in the treated group were also better (P＜0.05). Conclusion: TCM combined with CT could raise the patients' ability in tolerating CT in stage Ⅲ-Ⅳ NSCLC.