Objective To study the changes of serum levels of T-cell subgroups,cytokines and immunoglobulins on the pathogenesis of asthma in children,and explore the role of them in the pathogenesis of asthma. Methods Forty children with asthma (asthma attack group and asthma convalescence group) and 25 healthy children (control group) were enrolled in this study.The level of CD3+CD4+ and CD8+T-cell were determined using flow cytometry (FCM).The levels of TNF-α,IL-6,IL-8 and IgE were determined using ELISA, the level of IgG,IgA and IgM were detected by immunoturbidimetry.Results Compated with control group,there were higher levels of CD3+ and CD4+T-cell and CD4+/CD8+ in asthma attack group (P＜0.01),and higher levels of CD4+T-cell and CD4+/CD8+ in asthma convalescence group (P＜0.05),while no difference in the level of CD8+T-cell The level of CD4+T-cell and CD4+/CD8+ were higher in asthma convalescence group than those in control group (P＜0.05).The level so IL-6,IL-8 and TNF-αin asthma attack group were higher than those in asthma convalescence group and control group (P＜0.05 or＜0.01),the level of TNF-α was significantly higher in asthma convalescence than that in control group (P＜0.05).There were higher levels of IgE and IgG in astham attack group than those in asthma convalescence group and control group (P＜0.01 or＜0.05),the level of IgA was lower than than in conrtol group (P＜0.01).There was higher level of IgE in asthma convalescence group than that in control group (P＜0.01).Conclusions The immune imbalance exists in children with asthma at both attack and convalescence stages.A long-time anti-allergy trealment for childhood nsthma is necessary.