Abstract: Removal effects of micro-polluted Zhujiang river raw water by a combined process of activated carbon catalytic ozonation and biologically activated carbon(AC/O3-BAC) were investigated which was also compared with that of the combination of ozonation and activated carbon(O3-BAC). It was demonstrated that the AC/O3-BAC combined process showed great advantage in removing TOC、UV254 and NH3-N under optimum conditions (ozone dosage: 50 mg/h; gas flow: 200 L/min; oxidation time: 15 min). Under optimum conditions, the TOC and CODMn was removed by 28.5% and 50.3% respectively in AC/O3-BAC, increasing by 16.0% and 34.8% respectively compared with BAC alone, and increasing by 4.9% and 5.9% respectively compared with O3-BAC. Three processes showed great synergetic effect for organic pollutant removal, AC/O3-BAC was more efficient than O3-BAC and BAC in oxidating big molecule aromatic compounds to small molecule compounds, which increased biodegradability of oxidation effluent and reduced more organic compounds in subsequent BAC unit.