Cationic and silicon substituents are introduced into polysaccharides thereby producing modified polysaccharides cationically substituted by quaternary ammonium groups and having a charge density of about 0.1 to about 2.5 meq/g, and further substituted by siliconate groups such that the modified polysaccharide has a silicon content of about 300 to about 5000 ppm. The modified polysaccharides have application in industrial, home care and personal care surface modifying formulations.