In the paper industry, various types of paper strength agents have been widely used in order to improve the runnability of machines and also to achieve higher quality of product paper.In recent years. the branched type of copolymers, one of paper strength agents, has become more popular since it performs better than conventional agents in drainage and paper strength efficiency. As papermakers have been more seriously facing the strong economic demand of cutting costs, it may be one of the solutions for them to make full use of their machines by speeding up the process. Also considering the public demand for earth friendly industries, it is also important for us to make efforts to recycle used paper. Under such circumstances, we feel strong interests how we could satisfy such demands achieving the highly effective performance of paper strength agents at the same time.We are reporting the evaluation of the effects of various types of paper strength agents regarding drainage, formation, and quality of paper under several different papermaking conditions.