The Fe(II)/H²O₂ reagent is referred to as the Fenton's reagent, which produces hydroxyl radicals by the interaction of Fe(II) with H₂O₂. The powerful oxidizing ability and extreme kinetic reactively of the hydroxyl radical is well establiched. The objectives of this work are to find the applicability of the Fenton oxidation process for the reduction of COD from the papermaking wastewater and to investigate the effects of reaction conditions such as reaction time, pH, hydrogen peroxide dosage, and ferrous sulfate dosage on COD removal from wastewater. The Fenton oxidation was most efficient in the reaction time 90min, pH 3, hydrogen peroxide dosage 750mg/L, and ferrous sulfate dosage 300mg/L for COD 200mg/L papermaking wastewater.