Th2 cytokine is predominant in tumor patients and was found to be associated with tumor progression. Reversing of Th2 dominant status is thought to be a promising strategy. In the present study, peripheral blood mononuclear cells (PBMNC) of 37 lung cancer patients and 19 healthy subjects were prepared and used for examination of cytokine secretion and gene expression. The positive percentage of mRNA transcripts of Th1 cytokines (8.1% for IFNgamma and 13.5% for IL-2) in patients' PBMNC were lower than those of Th2 cytokines (70.3% for IL-4, 64.9% for IL-6 and 83.8% for IL-10). The gene expression capacity (measured as relative intensity to ratio of beta-actin) of patients for Th1 cytokines was low, but constitutively relatively high for Th2 cytokines. Both positive percentage and relative intensity were lower in transcript factor for Th1 cytokine, T-bet (40.5% and 0.139, respectively) than those for Th2 cytokine, GATA3 (89.2% and 0.364, respectively). Traditional Chinese medicine, Astragalus (AG) was observed to reverse Th2 status of lung cancer. AG enhanced culture supernatant and gene expression levels of Th1 cytokine (IFNgamma and IL-2) and its transcript factor (T-bet), and reduced those of Th2 cytokines in cultured PBMNC of lung cancer patients. These results demonstrated that traditional Chinese medicine AG might reverse the Th2 predominant status in lung cancer patients, which is a probable alternative therapeutic regime in future.