OBJECTIVE: To study the changes of serum levels of IgE, T-cell subgroups and cytokines in children with bronchial asthma during the stage of attack and convalescence. METHODS: The levels of T-cell subgroups were determined by the mono-clone antibody indirect-immuofluorence method and the levels of IgE, IL-2, IL-4, IL-6, IL-8 and IFN-γ were detected using ELISA in 45 children with asthma in the stage of attack and convalescence. Twenty healthy children served as the controls. RESULTS: Compared with the controls, there were higher levels of CD3+ and CD4+/ T cells and the ratio of CD4+/CD8+ in the 45 children with asthma in the stage of attack and convalescence ( P<0.05,P<0.01, P < 0.01, respectively), whereas there was no difference in the CD8+ T cell level. The CD4+ T cell level and the ratio of CD4+ /CD8+ of patients were higher in the stage of attack than those in the stage of convalescence ( P <0. 05). The levels of IL-2 and IFN-γ in the asthmatic children in the stage of attack were lower than those of the controls ( P <0.01 or 0.05) and the levels of IL-4, IL-6, IL-8 and IgE were higher than those of the controls ( P <0.01 or 0.05). In the stage of convalescence, the levels of IL-2 and IFN-γ were lower and levels of IL-4, IL-8 and IgE were higher than those of the controls ( P < 0.05 or 0.01), while no difference was noted in the IL-6 level. CONCLUSIONS: Children with bronchial asthma in the stage of both attack and convalescence have an imrnunologic imbalance. A longer-time anti-alergic treatment administrated for childhood asthma is necessary. [Chin J Contemp Pediatr, 2003, 5(1): 23-26]