1-Butyl-3-methylimidazolium chloride（［BMIM］［Cl］） ionic liquid was used as a novel electrolyte additive to prepare a prussian blue（PB） modified carbon paste electrode（ PB-IL/CPE）by electrodeposition method.The electrochemical property and kinetic characteristics of PB-IL/CPE were studied by cyclic voltammetry.The electrocatalytic reduction behavior of H2O2 on PB-IL/CPE was detected by chronoamperometry.The results demonstrated that the depositing current of PB was related to the concentration of ［BMIM］［Cl］，and the highest redox currents for PB electrodeposition were obtained at 0.2 mmol/L ［BMIM］［Cl］.Compared to PB/CPE electrode prepared in absence of ［BMIM］［Cl］，the PB-IL/CPE showed more powerful electrocatalytic reduction to H2O2，with wider linear detection range and higher sensitivity.In addition，the kinetics of PB-IL/CPE was also discussed.In comparison with that on PB/CPE，higher diffusion coefficient of K+（4.45×10-11 cm2·s-1） on PB-IL/CPE was obtained.