Bottle-point experiments were conducted in Huangpu river raw water to examine the extent to which chlorine influenced the ability of powdered activated carbon (PAC) to adsorb two kinds of microcystins (MC-RR and MC-LR). The result shows that,when adding PAC and chlorine at the same point, chlorine can enhance the removal effect of the combined process (about 20%), which may be because the surface of PAC catalyzes the reaction between mirocystin and chlorine molecule, when adding PAC and chlorine at different points, the strengthening effect disappear [chlorine reduces the ability of PAC to microcystins to some extent (5%-10%)], the effect of chlorine to PAC becomes weak when raise the dosage of PAC. PAC can effectively remove microcystins (the removal effect can reach 55% and 45% for MC-RR and MC-LR respectively at the dosage of 10 mg/L, contact time of 6 hours) when using PAC alone.