Catalytic cracking of paraffinic naphtha requires higher temperature than that for cracking of olefinic naphtha. In the high temperature catalytic cracking, thermal cracking also occurs simultaneously. The degree of thermal cracking and its contribution to ethylene and propylene yield in the catalytic cracking of paraffinic naphtha are experimentally investigated. As the degree of thermal cracking is high at over 650 degrees C, both thermal and catalytic cracking mechanisms have to be simultaneously considered in the kinetic model. An approximate approach based on transition state theory is proposed for kinetic modeling of the catalytic cracking of paraffinic naphtha, which has a complex chemical reaction network. The pertinent parameters of the developed kinetic model are estimated by a genetic algorithm. Additionally, an integrated modeling software package is developed with a graphical user interface. The efficacy of the proposed approach is shown with its application to industrial catalytic cracking of paraffinic naphtha in the circulating fluidized bed reactor system. This approach will be particularly effective for modeling complex chemical reaction network systems.