Abstract：Objective：To observe the clinical efficacy of modified Erchen Decoction combined with conventional western medicine in the treatment of chronic cough after mycoplasma pneumoniae infection （CCAMP） in children. Methods：A prospective randomized controlled trial design was adopted. A total of 196 children with CCAMP admitted to Jiaozuo Maternal and Child Health Hospital were randomly divided into the control group and the treatment group using the random number table method， with 98 cases in each group. Finally， 92 cases completed the study in the control group （2 dropped out，4 excluded），and 94 cases completed the study in the treatment group （1 dropped out， 3 excluded）. The control group received conventional western medicine treatment，while the treatment group received modified Erchen Decoction on the basis of conventional western medicine. After 14 consecutive days of treatment，the traditional Chinese medicine syndrome scores， cough symptom scores， and clinical efficacy were evaluated in both groups. Serum inflammatory factors and cellular immune function indicators were compared. The incidence of adverse reactions was also compared between the two groups. Results： After 14 days of treatment， the traditional Chinese medicine syndrome scores and cough symptom scores in both groups decreased compared with those before treatment， and the scores in the treatment group were lower than those in the control group （P＜0.05）. The serum levels of interleukin-4 （IL-4）， interleukin-6 （IL-6）， and tumor necrosis factor-alpha （TNF-α） in both groups decreased compared with those before treatment，and the serum levels of IL-4，IL-6，and TNF-α in the treatment group were lower than those in the control group （P＜0.05）. The levels of serum immunoglobulin [immunoglobulin A （IgA）， immunoglobulin M （IgM），immunoglobulin G （IgG）] in both groups increased compared with those before treatment， and the levels of IgA，IgM，and IgG in the treatment group were higher than those in the control group （P＜0.05）. The total effective rate of overall traditional Chinese medicine syndrome efficacy was 94.68% （89/94） in the treatment group and 83.70%（ 77/92） in the control group，with a statistically significant difference（ P＜0.05）. The incidence of adverse reactions was 6.38% （6/94） in the treatment group and 16.30% （15/92） in the control group， and the difference between the two groups was statistically significant （P＜0.05）. Conclusion：Modified Erchen Decoction combined with conventional western medicine in the treatment of CCAMP in children can effectively improve traditional Chinese medicine symptoms manifestations and cough symptoms， reduce inflammatory responses， enhance immunity， and have fewer adverse drug reactions. It is superior to conventional western medicine alone.