The purpose of this study was to estabilsh an optimum working condition to remove remaining organics and color by three steps : 1) Fenton oxidation 2) Complete mixing anaerobic process and aerobic fixed biofilm process 3) Fenton oxidation to remove the non-biodegradable organics and color remained after 2nd step. COD of leachate samples was 2,000㎎/L in average and their BOD-5/COD ratio were approximately 0.04. The COD removal obtained from the 1st Fenton oxidation previous to biological process was 60%. Methanol was added to an complete mixing anaerobic/aerobic fixed biofilm process to enhance a biological activity. Then an optimal dilution ratio was near to 50% and COD removal was 71.6%. Fenton oxidation as the 3rd step was conducted to exhibit a 52% of COD removal.