Abstract： Objective： To observe the clinical effect of oral ulcer powder combined with Yunnan Baiyao Capsule for recurrent oral ulcer. Methods：A total of 90 cases of patients with recurrent oral ulcer were randomly divided into the control group and the observation group，45 cases in each group. The control group was treated with Yunnan Baiyao Capsule，and the observation group was additionally treated with oral ulcer powder based on the treatment of the control group. After oneweek treatment，the clinical effect and the changes in Visual Analogue Scale(VAS) scores and levels of inflammatory factors including tumor necrosis factor(TNF) and interleukin- 6(IL- 6) in the two groups were evaluated. Results：The total effective rate was 97.78% in the observation group， and 84.44% in the control group， the difference being significant(P＜0.05). Before treatment， there was no significant difference being found in the comparison of VAS scores between the two groups(P＞0.05). After treatment， the VAS scores in the two groups were decreased when compared with those before treatment(P＜0.05)，and the VAS score in the observation group was lower than that in the control group(P＜0.05). Before treatment， there was no significant difference being found in the comparison of levels of TNF and IL- 6 between the two groups(P＞0.05). After treatment，the levels of TNF and IL-6 in the two groups were decreased when compared with those before treatment(P＜0.05)， and the two indexes in the observation group were lower than those in the control group(P＜ 0.05). Conclusion： Oral ulcer powder combined with Yunnan Baiyao Capsule has definite effect in treating recurrent oral ulcer，and can improve clinical effect，relieve pain and reduce levels of inflammatory factors.