A method has been developed for removing humic substances by hybrid ultrafiltration combined with both flocculation and adsorption treatments. Flocculation by use of poly aluminum chloride (PAC) was particularly effective for the removal of humic acids, which constitute the relatively high molecular weight fractions of humic substances, whereas adsorption by use of powdered activated carbon (PAC) was able to remove fulvic acids of relatively low molecular weight effectively, which could not be fully flocculated by PACI Consequently, the combined operation of flocculation and adsorption was extremely effective for the treatment of humic substances. It was shown that both flocculation and adsorption characteristics of humic substances were strongly influenced by the solution pH. Hybrid ultrafiltration in combination with flocculation and adsorption treatments exhibited high permeate flux with high permeate quality. It was found that the dosages of both PACI and PAC exert large effects on the filtration performance, suggesting that there exist optimum dosages of PACI and PAC.