Abstract：Objective：To observe the clinical effect of modified Jianpi Hewei Qingxian tang on erosive oral lichen planus. Methods： A total of 100 patients with erosive oral lichen planus were selected and divided into the control group and the observation group according to different treatment methods， with 50 cases in each group. The control group was treated with conventional western medicine， and the observation group was additionally given modified Jianpi Hewei Qingxian tang based on the treatment of the control group. The clinical effects in the two groups were evaluated， and the pain degree， lesion area， levels of serum inflammatory factors and immune function in the two groups were compared before and after treatment. Results：The total effective rate was 90.0% in the observation group，higher than that of 76.0% in the control group，the difference being significant(P＜0.05). After treatment，the scores of Visual Analogue Scale(VAS)， erosion area and congestion area in both groups were decreased when compared with those before treatment(P＜0.05)， and the VAS score， erosion area and congestion area in the observation group were lower than those in the control group(P＜0.05). After treatment， the serum levels of interleukin-1β(IL-1β)，interleukin-10(IL-10)，interleukin-18(IL-18) and tumor necrosis factor-α (TNF- α) in both groups were decreased when compared with those before treatment(P＜0.05). The serum levels of IL- 1β，IL-10，IL-18 and TNF- α in the observation group were lower than those in the control group(P＜0.05). After treatment，the levels of CD4+ and CD4+/CD8+ in both groups were increased，and the levels of CD8+ were decreased(P＜0.05). The levels of CD4+ and CD4+/CD8+ in the observation group were higher than those in the control group，and the level of CD8 + was lower(P＜0.05). Conclusion：Modified Jianpi Hewei Qingxian tang can reduce the pain degree， repair the ulcer surface， reduce the levels of inflammatory factors and improve the body immunity in patients with erosive oral lichen planus.