Abstract: For enhancing the treating effect of flocculants,polyquaternary ammonium acrylamide graft copolymer(PAQD) was prepared from acrylamide(AM) and poly2-hydroxylpropyldiethyl ammonium chloride and was used as flocculant in the treatment of dye house wastewater.The results showed that the removal rate of colourity,SS and CODcr was 92.1%,89.3% and 77.3% respectively under the conditions when temperature was normal,pH value was 7.0 and flocculant dosage was(7 mg/L).In comparison with conventional flocculants,such as anionic polyacrylamide(APAM) and nonionic polyacrylamide(NPAM),the flocculation performance of PAQD was the best.PAQD flocculant was characterized by less flocculant dosage,higher sedimentation rate,lower water content of filter cake and clearer supernatant.The flocculation effect of PAQD had a slight advantage over that of inward cationic polyacrylamide(CPAM).