Objective To investigate the syndrome differentiation characteristics of children with atopic dermatitis(AD)and the immune imbalance status in children with different syndrome types of AD.Methods A total of 159 AD children and 100 normal control children were enrolled.The peripheral blood eosinophil(Eo)count was measured by impedance method,total serum immunoglobulin E(IgE)by immunoturbidimetric assay,and interferon-gamma(IFN-γ),interleukin-4(IL-4),interleukin-5(IL-5)and interleukin-17(IL-17)were measured by multiple microspheres flow immunofluorescence assay.Results Among 159 AD children,syndrome of heart-fire and spleen-deficiency was most commom,accounting for 38.4%,followed by syndrome of blood-deficiency and wind-dryness(22.0%),syndrome of heat accumulation in heart and spleen(20.1%)and syndrome of spleen-deficiency and dampness-accumulation(19.5%).Compared with normal control group,there was no significant difference in serum IFN-γ level among different syndrome types of AD.The levels of peripheral blood Eo,serum total IgE,IL-4 and IL-17 in AD with heart-fire and spleen-deficiency syndrome were significantly increased(P<0.05).The levels of peripheral blood Eo,IL-4,IL-5 and IL-17 in AD with blood-deficiency and wind-dryness syndrome were significantly increased(P<0.05).The levels of IL-4,IL-5 and IL-17 in AD with heat accumulation in heart and spleen syndrome were significantly increased(P<0.05).The levels of peripheral blood Eo and serum IL-4 in AD with spleen-deficiency and dampness-accumulation syndrome were significantly increased(P<0.05).Conclusion Heart-fire and spleen-deficiency syndrome is the most common type in children with AD,however,the main type under 3 years old is heat accumulation in heart and spleen syndrome.Th2/Th17 immune imbalance are the main pathogenesis in heart-fire and spleen-deficiency syndrome,blood-deficiency and wind-dryness syndrome and heat accumulation in heart and spleen syndrome,and Th2 immune imbalance is the main pathogenesis of spleen-deficiency and dampness-accumulation syndrome.