Sodium carboxy cellulose particles are negatively charged. The degree of electrophoretic mobility depends upon storage time. Increase of polymer concentration resulted in electrophoretic mobility decrease which becomes constant at rather high concentrations. Electrophoretic mobility is lower at low pH values. During storage, electrokinetic changes occur, being more significant in solutions having higher pH values. In all the cases of sodium carboxy methyl cellulose concentrations used, electrokinetic changes during storage are slight. -- AATA