Textile industry is one of the major sources in polluting the nature’s gift (water) to mankind. In textile industry the dyeing process is the main process which pollutes water. Large quantities of water are used up in this process which produce large amount of waste water. This waste water has high turbidity caused by Dyes. Almost all of these dyes are not consumed properly. Therefore treatment processes are required to clean up the textile waste water. In the present work a new flocculant was prepared which is cheap and its impacts on the treated water are not harmful. It was prepared by reacting the corn starch with hydroxymethyl dimethylamine hydrochloride by dry process. Then It was used as flocculant to study the behaviour of flocculation. It was used to treat dyestuff (Reactive Acid yellow C.I. 13065) wastewater. The effects of coagulant dosage and residence time on the flocculation were studied and it was found that the dyestuff flocculation reached at optimum. The effect of temperature on the preparation of HMMAHC was also studied. The results depicts that this flocculant has high adsorption efficiencies.