【Abstract】Objective To explore the correlation between the imbalance of peripheral blood h17 cells and Treg cells and Epstein-Barr virus (EBV) infection in children. Methods Fifty-eight children with EBV infection treated in the Pediatric Outpatient Department, The First Hospital of Qinhuangdao during the period from December 2019 to May 2020 were enrolled in the study. Meanwhile, 50 healthy children were selected as the control group. Fasting venous blood was collected to detect the expression rates of peripheral blood Th17 cells and Treg cells, relative expression levels of RORγt mRNA and Foxp3 mRNA, and levels of cell-related characteristic cytokines IL-17 and TGF-β1. Results The expression rate of peripheral blood Th17 cells in EBV infection group was significantly higher than that in control group, and the expression rate of Treg cells and Treg/Th17 ratio were significantly lower than those in the control group (P＜0.05). The expression rate of RORγt mRNA in EBV infection group was significantly higher than that in the control group, but the expression rate of Foxp3 mRNA was significantly lower than that in the control group (P＜0.05). The IL-17 level in EBV infection group was significantly higher than that in the control group, and TGF-β1 level was significantly lower than the control group (P＜0.05). Conclusion The incidence of EBV infection in children is closely related to the imbalance of Th17 cells and Treg cells as well as changes of related characteristic cytokines.