The equations for catalytic wave at ultramicrodisk electrode with linear sweep voltammetry and constant potential voltammetry are derived. It is shown that when krcz* (where kf is the rate constant for the chem. reaction, cz* is the concentration of catalyst) is larger, the same current-potential relations can be obtained. Experiments were carried out on platinum ultramicrodisk electrode to verify the theory. Theor. conclusions are in good agreement with experimental data for the oxidation of K4Fe(CN)6 in antipyrine-KOH solution The rate constant for catalytic reaction (kf) is also determine

Key words: CATALYSIS, REACTION KINETICS, REACTION RATE CONSTANT, POTASSIUM FERROCYANIDE, POTASSIUM HYDROXIDE, TROPICAL FOREST, AMINOPYRINE, ELECTRODE PROCESS