Abstract：Objective：To observe the clinical effect of the gargle of Kangfuxin Liquid on recurrent oral ulcer (ROU) based on routine treatment measures and external application with Xilei Powder. Methods：A total of 120 ROU patients were selected as the research objects and divided into the combination group and the control group by the random table number method，with 60 cases in each group. The two groups were given routine treatment measures and external application of Xilei Powder，and the combination group was additionally treated with the gargle of Kangfuxin Liquid. The two groups were treated for 7 days. Before treatment and after 3 and 7 days of treatment，the scores of Visual Analogue Scale (VAS) for pain of the lesion area of oral ulcer were evaluated， and the ulcer area and congestion area of mucosa around ulcer sites were measured. The clinical effects in both groups were compared. Results： After 7 days of treatment， the total clinical effective rate was 98.33% in the combination group， higher than that of 83.33% in the control group， the difference being significant (P＜0.05). After 3 and 7 days of treatment， there was a trend that the VAS scores were decreased and the ulcer area and congestion area in both groups were reduced when compared with those before treatment， differences being significant (P＜ 0.05)；the VAS scores for pain at the above two time points in the combination group were lower than those in the control group respectively，and the ulcer area and congestion area were smaller，differences being significant (P＜0.05). After 7 days of treatment， the VAS scores in both groups were decreased when compared with those after 3 days of treatment， and the ulcer area and congestion area were reduced， differences being significant (P＜0.05). Conclusion： Based on routine therapy and external application of Xilei Powder， the gargle of Kangfuxin Liquid has a sound curative effect on ROU， which can quickly mitigate the local pain of oral ulcer and accelerate the recovery of ulcer area.