Since for some years chitosan is in the focus of biologically orientated research. It has a huge number of advantages compared to synthetic products. In this work the chitosan was reacetylated and afterwards characterized. Reacetylated chitosan dissolves in deionized water without any additives and shows good flocculation properties. Furthermore the properties of flocculation were compared to commercial chitosan. Molar mass, pH value, and the salinity in the system have great influence on position and width of the flocculation window.