AA/AMPS is the copolymer of acrylic acid and 2-acrylanmido-2-methylpropanesulfonic acid (AMPS). Due to including carboxylic group (scale inhibition and dispersion) and sulfonic acid group (strong polarity) in this copolymer, AA/AMPS has high calcium tolerance, good dispersity and good scale inhibition for calcium carbonate, zinc scale, calcium phosphate in particular, in the water system. Its excellent dispersing performance enables it to prevent the sedimentation of iron oxide effectively. When built with organophosphines, the synergic effect is obvious. AA/AMPS is suitable to be used in water quality of high pH and high alkaline. It is one of the most ideal scale inhibitor and dispersant on high concentration index.