Chronopotentiometric measurements were carried out with a polished gold electrode in order to follow the catalytic oxidation of ferrocyanide ions by ceruloplasmin in the presence of dissolved oxygen. By using the representations which apply for the conventional treatment of Michaelis-Menten reaction scheme, data were successfully analyzed via the variations of nernstian equilibrium potentials with time. An alternate procedure based on chronopotentiometric measurements achieved in particular conditions of substrate and time duration was proposed from which the kinetic rate constants, K(m) and V(m), could be directly deduced after numerical calculation. This procedure should apply to any oxidase mediated enzymatic kinetics involving substrates bestowed with redox properties.