Anionic Polyacrylamide is a kind of soluble high molecular weight polymer or polyelectrolyte. Having several polar groups in the molecular chain, it can form bridge among particals by absorbing suspended solid particals in wastewater and condense particle into big flocs by neutralizing charges. Therefore, it can speed up sedimentation of particles in suspensions and excels in speeding up purification of solutions and promoting filtration and so on.