Objective：To investigate the expression of Th1/Th2 cytokines in peripheral blood of patients with oral lichen planus（OLP） and to discuss the role and significance of Th1/Th2 cytokines in the pathogenesis of OLP. Methods：Totally 51 cases of OLP with dif－ferent clinical characters（including 23 cases of reticular OLP and 28 cases of hyperaemia erosion OLP） were enrolled. Cytometric bead array was employed to detect the level of type 1 cytokines（TNF-α，INF-γ，IL-2） and type 2 cytokines（IL-4，IL-6，IL-10） of T helper cells in serum of patients with OLP. The relationship between the levels of these cytokines and the clinical characteristics of patients with OLP was analyzed. Results：Expression levels of IL-6 and IL-10 in the peripheral blood of patients with OLP were sta－tistically increased compared with those of controls（P＜0.05），but no statistical difference was observed in level of Th1 cytokines（TNF-α，IFN-γ，IL-2） and IL-4 between OLP patients and controls（P＞0.05）. Expression levels of IL-6 and IL-10 were positively correlated with clinical characters（r：0.285-0.364；P＜0.05）. Conclusion：Th1 cytokines remain unchanged and Th2 cytokines increase in OLP patients，showing the advantage of Th2 immune response. Levels of IL-6 and IL-10 are positively correlated with disease severity，which may be helpful for OLP immunotherapy.