In this article, partial oxidation of sodium alginate with potassium permanganate (KMnO4) was researched successfully. The effects of KMnO4 on the properties of partially oxidized sodium alginate were discussed. It was found that the degree of oxidation and degradation rate of sodium alginate could be controlled by oxidation conditions, as monitored by the reduction of viscosity and decrease of molecular weight. This work provides a new method to obtain partially oxidized alginate and to improve degradability of alginate for biomedical applications, (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113:3585-3589, 2009