Abstract: Cobalt and nickel give sensitive adsorption catalytic waves in the system of NaOH-Nioxime-NH₄Cl-NaNO₂. The height of the catalytic waves is directly proportional to the concentration of Co and Ni in the range of 0.025-2 ppb and 1-100 ppb respectively.The detection limit is 0.02 ppb for Co, 0.33 ppb for Ni. Various conditions and mechanism of catalytic waves of Co and Ni in this system have been studied in detail. An analytic method of consecutive determination of trace Co and Ni was proposed.