Polyacrylamide is called as PAM for short and it is polymerized by the acrylamide monomer. PAM is a kind of linear water-soluble polymer matter. With different techniques and functional groups, products with different types of charge can be obtained, including the anionic polyacrylamide (APAM), cationic polyacrylamide (CPAM), non polyacrylamide (NPAM) and amphoteric polyacrylamide (ACPAM). The average molecular weight of PAM ranges from thousands to millions and it is the high-molecular electrolyte. It is the white power or granule, and it can be dissolved in the water easily but not the common organic solvents including the benzene, ether, ester, acetone, etc.. The aqueous solution of polyacrylamide is the thick liquid, and it is non-toxic and non-corrosive. The solid PAM is hygroscopic, and the hygroscopicity is improved with the increasing of ionic degree. Use characteristics 1) Flocculability: The PAM plays the role of flocculation for the suspended matter through electrical neutralization, bridging and adsorption. 2) Adhesivity: It has the adhesive effect based on the mechanical, physical and chemical role. 3) Resistance reducing: PAM can effectively reduce the frictional resistance of fluid, and adding a minute amount of PAM into water can reduce the resistance by 50-80%. 4) Thickening: PAM has the effect of thickening both under the neutral and acid conditions. When the pH is greater than 10, PAM can have the easy hydrolysis. Besides, the effect of thickening will be more obvious when the PAM has the semi-mesh structure.