The oxidation of sugars was monitored spectrophotometrically by potassium permanganate in acidic medium at ?max 545 nm. Oxidation products were identified as arabinonic and formic acid and the respective acids of sugars. These products may be due to the generation of two oxidative species of Potassium Permanganate in acidic medium. Respective acids of sugar by the generation of reactive oxygen species in presence of an acid and arabinonic and formic acids due to the breakage of C__C bond by the reactive species of Permanganate ion. Slow reaction of lactose was accelerated by catalyzing it with Hg. Negligible effect of varying salt electrolyte concentration showed that the molecular species is involved in the rate determining step. Reaction was also studied at various temperatures and activation parameters were determined.