The treatment of landfill leachate by Fenton process was investigated. Experiments were conducted in a batch reactor to examine the effects of operating factors including pH, hydrogen peroxide concentration and ferrous ion concentration on chemical oxygen demand (COD) of treated leachate. The optimal reacting conditions were experimentally found to be ［Fe2+］=4 mmol/L, ［H2O2］/［Fe2+］=16 and pH=3 at room temperature. Under these conditions, the initial COD of the leachate was reduced by about 40% within 4 h. The bioavailability of the leachate was improved after Fenton oxidation, as indicated by its BOD5 /COD ratio to be larger than 0.5. In addition, Fenton oxidation used in this process conforms to two-stage the pseudo-first-order kinetic model.