Reduced kinetic equations for a CO/H-2/air oxidation model have been constructed by a special perturbation method (SPM) developed recently by the authors. The SPM is a modification of the constrained nonlinear lumping approach to the simplification of kinetic models. The reduced kinetic equations are only composed of the variables for the temperature and the concentrations of main species (CO, H-2, O-2, CO2 and H2O), and retain high accuracy in the solutions. All the eliminated variables, the concentrations of radicals and other unimportant species, can be also accurately calculated from the solutions of the reduced kinetic equations by employing some algebraic expressions. The SPM gives significantly better results than the traditional quasi-steady-state approximation when the latter breaks down.