Performance improvement of a catalyst regenerator for gasoline production in a fluid catalytic cracking (FCC) process is needed to achieve higher burning efficiency. This study performed a systematic model-based analysis of a downer-type regenerator to recover the activity of FCC catalyst by using a one-dimensional model of the regenerator coupled with its hydrodynamic characteristics and the kinetics of catalyst regeneration. The results of a sensitivity analysis showed that higher carbon content on spent catalyst causes a higher regeneration temperature. The ratio of the recycled-to-spent catalyst flow rate in range of 1.0-3.5 and temperatures of the spent catalyst in range of 703.15-803.15K have insignificant effects on the overall performance of the regenerator. The suitable superficial gas velocity and the spent catalyst flow rate are in range of 4-7ms-1 and 20-40kgm-2s-1, respectively. © 2012 Elsevier Ltd.