OBJECTIVE To observe the effect of moxa-grain-moxibustion on serum IL-2 and IL-10 levels and T-lymphocyte proliferation activity in Lewis tumor-bearing mice, so as to reveal its mechanism underlying improvement of immune function under lung cancer condition. METHODS Thirty Lewis tumor-bearing mice were randomly divided into control group, tumor-bearing model group and moxibustion group (n = 10 in each group). Lung tumor model was established by subcutaneous inoculation of Lewis tumor cell suspension (0. 2 mL). The ignited moxa-grain was applied to bilateral "Housanli" (ST 36) one session a day for 10 sessions. The animals' daily life activity and the lung tumor growing status were observed every day. MTT [3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide] colorimetry was used to determine T lymphocyte proliferation activity, and serum IL-2 and IL-10 contents were detected by ELISA. RESULTS Following moxibustion, no statistical differences were found in the gross tumor volume and body weight between tumor-bearing model and moxibustion groups and between pre-moxibustion and post-moxibustion in the same one group (P>0.05). Compared with the blank control group, serum IL-2 content in the model group were significantly decreased (P<0. 05),while serum IL-10 level was significantly increased in the model group (P<0. 05). After moxibustion, the T-lymphocyte proliferation rate and serum IL-2 were markedly increased(P<0. 05), but serum IL-10 level was considerably decreased in the moxibustion intervention group in comparison with the tumor-bearing model group(P<0. 05). CONCLUSIONS Moxa-grain-moxibustion can effectively up-regulate T lymphocyte proliferation activity and balance Th 1/Th 2 in tumor-bearing mice, suggesting an enhancement of the body's anti-tumor ability after moxibustion.