Abstract: Objective To observe the changes of immune cell function in children with Mycoplasmal pneumoniae pneumonia(MPP). Methods Thirty-one children with MPP were divided into the acute stage group(n=14)and the convalescent stage group(n=17). The changes of immune cell function and related indicators(CD3⁺, CD4⁺, CD4⁺/CD8⁺, CD19 and CD56)were compared in the two groups. Results The expression levels of CD3⁺, CD4⁺, CD4⁺/CD8⁺, CD19 and CD56 in the acute stage group were all lower than those in the recovery stage group, and the differences were statistically significant(P< 0.05). Conclusion Detection of immune cell function related indicators in MPP children can effectively evaluate the disease condition and improve the cure rate.