Abstract：Objective：To discuss the effect of Sangju yin combined with cefaclor dispersible tablets for acute bronchitis in children and its mechanism. Methods：A total of 98 cases of children with acute bronchitis were divided into the control group and the observation group according to the random number table method，49 cases in each group. The control group was treated with cefaclor dispersible tablets， and the observation group was additionally treated with Sangju yin based on the treatment of the control group. The curative effect and the disappearance time of clinical symptoms including cough，fever，expectoration and rales as well as the levels of immunoglobulin G(IgG)， immunoglobulin A(IgA)， interleukin- 4(IL- 4) and interferon- γ(IFN- γ) and the Th1/Th2 before and after treatment in the two groups were compared. Results： The total effective rate was 97.96% in the observation group，higher than that of 85.71% in the control group，the difference being significant(P＜0.05). The disappearance time of clinical symptoms including cough， fever， expectoration and rales in the observation group was shorter than that in the control group， differences being significant(P＜0.05). Before treatment，compared the levels of IgG，IgA，IL- 4 and IFN- γ and the Th1/Th2 in the two groups，there being no significance in the difference(P＞0.05). After treatment，the levels of IgG，IgA and IFN-γ and the Th1/Th2 in the two groups were higher than those before treatment， and the levels of IL- 4 were lower； the levels of IgG， IgA and IFN- γ and the Th1/Th2 in the observation group were higher than those in the control group，and the level of IL-4 was lower；differences being significant (P＜0.05). Conclusion：The therapy of Sangju yin combined with cefaclor dispersible tablets has significant effect in treating children with acute bronchitis，and can effectively improve cure rate and immune function and shorten the course of disease， which is safe，feasible and worthy of clinical promotion and application.