Scale is agglomerate of thin film compounded of soluble salts in papermaking process. It causes many problems such as closing up pipelines, contaminating wire and felt, decreasing efficiency of additives and paper quality. In this study, physical factors related to forming scale in white water are determinated and optimum conditions are proposed. To control scale, ACP(Acrylacid Copolymer)was synthesized and compared with conventional chemicals such as EDTA, DTPA and STPP.