Application of multivariate regression methods for catalimetry simultaneous determination of iridium (IV) and rhodium (III) based on oxidation of N-methyldiphenylamine-4-sulphonic acid by periodations in weak acid medium was investigated. The data structure of the kinetic measurement was studied with Principal Component Analysis, it was found that the distribution of the samples corresponds to an increase in the total concentration of the catalysts of the PC1 and change the concentration ratio Ir: Rh on PC2.