Abstract: Objective To investigate not only the prevalence of Th17 and Treg cells related cytokines but also mRNA expression of RORγt and FoxP3 in patients with non-small-cell lung cancer.Methods We analyzed peri-pheral blood mononuclear cell(PBMC)of 57 patients with non-small-cell lung cancer and 25 healthy volunteers. Expressions of RORγt and FoxP3 mRNA in PBMC were determined by quantitative fluorescence PCR. The level of plasma TGF-β,IL-17A and IL-6 were measured by ELISA.Results The level of RORγt mRNA in patients with Stage Ⅳ((11.30±4.07)×10^-4) were higher than those in healthy volunteers ((7.50±2.75)×10^-4) and in patients with non-small cell lung cancer stage Ⅰ-Ⅲ ((5.18±2.10)×10^-4)(q=7.53,q=6.82;all P<0.01). The level of plasma TGF-β [(69.52±10.04)pg/ml] in patients with Stage Ⅳ was higher than that in patients with Stage Ⅰ-Ⅲ [(42.24±16.64)pg/ml] and healthy volunteers [(24.51±10.96)pg/ml](q=3.91,q=3.87;all P<0.05). However,there was no difference in the level of plasma IL-17A and IL-6 among these three groups(q=1.19,1.76,1.06; all P>0.05).Conclusion The elevated RORγt mRNA expression and level of plasma TGF-β were associated with disease progress,which indicated Th17 and Treg cells may play an important role in the antitumor immunity of non-small cell lung cancer.