Inferior residues can be effectively upgraded over a special catalyst in a fluidized-bed reactor to provide feedstock with trace metals and a few asphaltenes for downstream processes. A new eight-lump kinetic model was proposed to describe the reaction behaviors of upgrading residue by fluid carbon rejection. In this reaction system, the residue (>500 degrees C) was cut into four lumps according to saturates, aromatics, resins, and asphaltenes to expand the model to various feedstock. Moreover, the model took into account gas oils (350-500 degrees C) secondary cracking reactions. The experimental data were obtained in a fixed fluidized-bed reactor. The kinetic constants were estimated on the basis of Marquardt's algorithm. The apparent activation energies were calculated through the Arrhenius equation. This model fitted the experimental data well. Furthermore, model simulations were carried out to determine the effects of such parameters on product yields, as reaction temperature, weight hourly space velocity, and along the reactor height, which were helpful for optimizing the yields of desired products.