A kinetic model of straight-run gasoline catalytic cracking was developed according to the structure oriented lumping method. Seventy-six kinds of molecules were selected to describe feedstock, and 72 reaction rules were established to construct reaction networks in this model. After the reaction rate constant and the termination condition of the network were involved, product distribution, group composition, and octane number of gasoline could be predicted. In this work the laboratory test data of straight-run gasoline catalytic cracking by a fixed fluid bed unit was used to verify the model. The results showed that the predicted product distribution and group composition of gasoline agreed well with the experimental data.