The oxidation of arginine by chromic acid in presence of sulphuric acid in aqueous medium is reported here. The reaction is of first order with respect to substrate and total order is second with oxidant and substrate respectively. The oxidation reaction of arginine was studied at different acid concentrations. The products are carbondioxide, ammonia and g-guanidino butanaldehyde. The rate of oxidation increases with increase in the concentration of acid. The dielectric constant, activation energy and catalytic constant are calculated. The suitable mechanism has also been postulated.