The kinetics of oxidation of methyl cellulose polysaccharide as a natural polymer by alkaline potassium ferricyanide at a constant ionic strength of 1.0 mol dm(-3) have been studied, spectrophotometrically. The experimental results showed complex kinetics where the pseudo first-order plots were found to be straight lines up to 60% of reaction completion, and then deviated from linearity. A first-order dependence in Fe(CN)(6)(3-) and fractional first-order kinetics with respect to the methyl cellulose concentration was observed. The oxidation reaction was found to be base catalyzed. Again, addition of Fe(CN)(6)(4-) product to the reaction mixture leads to a remarkable retardation of the oxidation rates. A kinetic evidence for the formation of 1:1 intermediate complex was revealed. The activation parameters have been evaluated and a tentative reaction mechanism in good consistency with the kinetic results is discussed. (C) 2011 Elsevier B.V. All rights reserved.