The reaction rates of oximation of cyclohexanone by aqueous hydroxyl ammonium sulphate solutions with sodium dodecyl sulphate (SDS) as a micellar catalyst were measured in an agitated vessel with a flat interface. The reaction rates observed under various liquid compositions could be reasonably explained by a theoretical model, allowing for the reactions in the micellar and bulk phases and the distribution of the relevant species between the micellar and bulk phases. This oximation was accelerated by the solubilization of cyclohexanone and the other relevant species, and the apparent reaction rate constant in the micellar phase much larger than that in the bulk phase, yielding an overall reaction rate of about 3 times with SDS micellar catalyst than without it. The evaluated total apparent reaction rate constants were dependent on the pH in the aqueous solution, and were found to have a maximum value at a pH of about 5.0.