The purpose of this study is to investigate the operating parameters to impact of operating parameters in plasma reactors. in order to increased products of hydrogen peroxide in this system. The dielectric barrier discharge(DBD) plasma reactors was used in this study. the influent gas was divided into air and oxygen. the produced hydrogen peroxide concentration was analyzed and compared the operating condition of the parameter(Primary voltage, flow rate, secondary voltage, NaCl concentration, pH). In the same operating conditions, the produce amounts of hydrogen peroxide in oxygen plasma was higher than that in air plasma. the production of Hydrogen peroxide increased rapidly in the early 1minutes. the production of Hydrogen peroxide was increased with increasing NaCl concentration, primary voltage and secondary voltage. the production of Hydrogen peroxide was increased with increasing more acidic pH.