Abstract： Objective： To observe the effect of the therapy of modified Yinqiao San combined with antibiotics on acute tonsillitis in children and its influence on the levels of inflammation and immune function. Methods：A total of 100 children with acute tonsillitis of intense lung and stomach heat type were selected as the study objects， and were divided into the control group and the observation group according to different treatment methods， with 50 cases in each group. The control group was given Amoxicillin and Clavulanate Potassium for Suspension， and the observation group was additionally treated with modified Yinqiao San based on the treatment of the control group. The clinical effects and improvement time of symptoms in the two groups were observed， and the changes of inflammation levels， including tumor necrosis factor - α (TNF - α) and serum C-reactive protein (CRP)， and immune function were compared before and after treatment . Results： The total effective rate was 96.00% in the observation group and 80.00% in the control group，the difference being significant (P＜0.05). The time of fever regression，the mean time of pus disappearance and the time of laryngeal nucleus narrowing in the observation group were shorter than those in the control group，differences being significant (P＜0.05). After 7 days of treatment， the levels of TNF - α and CRP in the two groups were decreased when compared with those before treatment (P＜0.05)，and the levels of TNF- α and CRP in the observation group were lower than those in the control group (P＜0.05). After 7 days of treatment，the number of CD4+ T cells and the ratio of CD4+ T cells to CD8+ T cells in the two groups were increased when compared with those before treatment (P＜ 0.05)；the number of CD4+ T cells and the ratio of CD4+ T cells to CD8+ T cells in the observation group were higher than those in the control group (P＜0.05). There was no significant difference in the number of CD8+ T cells between and within the two groups (P＞0.05). Conclusion： The additional application of Yinqiao San based on antibiotics can improve the clinical effect on acute tonsillitis in children， alleviate the early symptoms，reduce the levels of inflammation，and improve the immunity.