AbstractIn this work thermodynamic analysis of catalytic cracking reaction involving the high molecular weight hydrocarbons was carried out using quantum chemical method of calculation realized in Gaussian software. The method of calculation is DFT (Density Functional Theory), theoretical approximation is B3LYP model, 3-21G basis. The list of catalytic cracking reactions for calculation was prepared on the basis of the theoretical data about catalytic cracking, laboratory and experimental data from the industrial unit. The enthalpy and Gibbs energy values of the main catalytic cracking reactions are presented under the process conditions. The results of this work will be used to develop a kinetic model of catalytic cracking of petroleum feedstock.