2-acrylamido-2-methylpropane sulfonic acid (AMPS) is commonly used in the synthesis of polyacrylamide which is widely used as surface-active agents, water treatment chemicals and oil-displacing agents. In the production process of AMPS, there are some byproducts. In this paper, the residue from AMPS production is analyzed. The main byproducts in the residue are ascertained by means of HPLC and ESI-MS, which are butylacrylamide (TBAA) and acrylamide. By external standard method, the residue is analyzed quantitatively. Using the residue as raw materials, a kind of polyacrylamide with low molecular weight is synthesized, which can be used as paper reinforcing agent or emulsifier. After the residue is purified, the high molecular weight polyacrylamide is synthesized, which can be used as flocculating agent or oil-displacing agent.