A novel methodological approach for the determination of catechol based on a Belousov-Zhabotinskii type oscillating system is presented. Such an oscillating reaction involves the oxidation of malic acid in an acidic bromate medium in the presence of a catalyst—macrocyclic complex [CuL] (ClO₄)₂. The unsaturated ligand L in the complex [CuL] (ClO₄)₂ is 5,7,7,12,14,14-hexemethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. By perturbation of catechol on the oscillating chemical reaction, the increase in the oscillation amplitude is linearly proportional to the logarithm of the concentration of catechol in the range 2.1 × 10⁻⁶–2.1 × 10⁻⁴ M, with a correlation coefficient of 0.9976. The R.S.D obtained for 7.88 × 10⁻⁵ M catechol is 3.8% (n = 5). Cyclic voltammetry was applied to explore the mechanism of catechol perturbation on the oscillating chemical reaction.