Abstract： Objective： To observe the clinical effect of Chinese medicine decoction combined with western medicine for recurrent oral ulcer (ROU) in children with accumulated heat in the spleen and stomach syndrome. Methods： A total of 124 cases of children with ROU with accumulated heat in the spleen and stomach syndrome were divided into the treatment group and the control group according to the random number table method， with 64 and 60 cases in each group respectively. The control group was treated with routine western medicine， and the treatment group was additionally treated with Chinese medicine decoction based on the treatment of the control group. The traditional Chinese medicine (TCM) syndrome scores and immune function indexes before and after treatment as well as the clinical effects， improvement time of symptoms and recurrence rates were evaluated in the two groups. Results：The total effective rate was 96.88% in the treatment group， higher than that of 85.00% in the control group (P＜ 0.05). Before treatment， there was no significant difference being found in the comparison of TCM syndrome scores between the two groups (P＞0.05)；after treatment，TCM syndrome scores in the two groups were lower than those before treatment (P＜0.05)，and the score in the treatment group was lower than that in the control group (P＜0.05). After treatment， the disappearance time of pain and the healing time of ulcer in the treatment group were shorter than those in the control group (P＜0.05). Before treatment， there was no significant difference being found in the comparison of levels of CD3 + ， CD4 + ， CD8+ and CD4+/CD8+ between the two groups (P＞0.05). After treatment，the levels of CD3+，CD4+，and CD4 +/CD8 + in the two groups were increased (P＜0.05)，and the CD8 + levels were decreased (P＜0.05)； the levels of CD3 +，CD4 +，and CD4 +/CD8 + in the treatment group were higher than those in the control group (P＜0.05)，and the CD8+ level was lower than that in the control group (P＜0.05). The recurrence rate was 6.45% in the treatment group，lower than that of 23.53% in the control group (P＜0.05). Conclusion： Chinese medicine decoction combined with western medicine has a definite effect on the treatment of children with ROU with accumulated heat in the spleen and stomach syndrome， which can alleviate the clinical symptoms of children，promote ulcer healing，improve the immunity of children，and reduce the recurrence rate.