Background: Lichen planus (LP) is a common chronic superficial skin lesion that causes chronic or sub-acute inflammatory disorders. LP can affect the oral cavity, skin, mucous membrane, and other body parts, and features include repeat attacks and long duration, leading to lower quality of life. This study aimed to analyze the changes of immunologic function before and after treatment of LP. Material/Methods: Thirty cutaneous LP patients were selected. Peripheral blood was collected in the morning before and after treatment. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient method. Flow cytometry was used to detect T cell subpopulation CD4(+)T cells and CD8(+)T to calculate CD4(+)T/CD8(+)T ratio. Enzyme-linked immunosorbent assay (ELISA) was adopted to detect the helper T-cell (Th) factor IL-2, IFN-gamma, IL-4, IL-6, IL-17, and IL-22 levels. Results: Compared with before treatment, the expressions of CD4(+)T cells and CD8(+)T cells were decreased, while the proportion of CD4(+)T/CD8(+)T were significantly elevated after treatment. IL-2 and IFN-gamma secretion were markedly increased, whereas IL-4, IL-6, IL-17, and IL-22 were significantly reduced after treatment (P<0.05). Conclusions: LP treatment reduces the distribution of CD4(+)T cells and CD8. T cells, and promotes the changes of Thl, Th2, and Th17 cytokines secretion.