Objective To explore the action of immune function in benign infantile convulsions with mild gastroenteritis (BICE) pathogenesis by detecting the T cell activation and cytokine of BICE.Method Thirty-one infant patients with BICE hospitalized in the wards of department of neurology of The Children' s Hospital Zhejiang University School of Medicine from April 2012 to April 2013 were selected as the experiment group,while 23 healthy infants accepting health check-up in the same period were selected as the control group.Flow cytometry was adopted to detect the peripheral blood CD25 +/CD3 + CD4 +,CD69 + /CD3 +CD4 +,HLA-DR/CD3 + CD4 +,CD25 +/CD3 + CD8 +,CD69 +/CD3 + CD8 +,HLA-DR/CD3 + CD8 +,and IL-2,IL-4,IL-6,IL-10,TNF-α,INF-γlevels of the two groups.Results The peripheral blood HLA-DR/CD3 + CD4 +,HLA-DR/CD3 + CD8 + expression levels (7.300％ + 2.725％,29.560％+ 14.079％) of the experiment group were higher than those of the control group (t =2.110,2.649,P =0.040,0.011); the expression level of the peripheral blood IL-10 was 8.100 (5.800-19.700) pg/ml,which was significantly higher than that of the control group (z =-3.342,P ＜ 0.01).Conclusion There is a certain degree of immune dysfunction in BICE patients,and T cell activation subgroup and the cytokines may participate in the morbidity progress of BICE.