Abstract: UV-Vis absorption spectra of aqueous solutions containing both metalloporphyrin Zn(X)TMPyP4 [H₂TMPyP4—5,10,15,20-tetrakis(1-methylpyridin-4-yl)-21H,23H-porphyrin] and synthetic polyadenylic-polyuridylic acid Poly(A)·Poly(U) over the temperature range from 20 to 70°C (pH = 7.0, I = 0.15 M.) have been analyzed. Deconvolution of the spectrometric data matrix, without postulating a physicochemical equilibrium model, has allowed estimation of the contribution of the Poly(A)·Poly(U)·(ZnTMPyP4)_n complex to the total change in the spectra. Chemometric analysis has shown an increase in the melting temperature of this ternary complex by 9.4°С compared to pure polyribonucleotide, which indicates the stabilization of the bonds between nucleic bases in the Poly(A)·Poly(U) polynucleotide under the influence of bound porphyrin.