The detailed chemical reaction kinetics mechanisms of iso-octane and n-heptane were simplified by using the methods of reaction path analysis and sensitivity analysis. With adopting the semi-decoupling methodol? ogy，the small molecule mechanism of C0~C1 was used as the core of primary reference fuel（PRF）for gasoline，a new reduced mechanism of PRF which consists of 41 species and 131 reactions was developed，and then the devel? oped mechanism was verified by the experimental data of shock tube（ST），laminar flame speed（LFS）and jet stirred reactor（JSR）. The results show that the reduced PRF chemical reaction mechanism developed in this paper can not only accurately predict the ignition delay time，but also effectively describe the laminar flame velocity and the evolution of key species.