A three-dimensional numerical model is developed to simulate gasification of combustible solid waste in a spouted bed. Both complex gas-solid flow and chemical reactions are considered. The particle motion is modelled by the Lagrangian method and the gas motion by the large eddy simulation (LES) turbulent model. Calculations were carried out in a cylindrical spouted bed with a diameter of 160mm, a height of 900mm, and a conical base of 60 degrees. Effects of equivalence ratio (ER) on product gas compositions were investigated. The flow patterns, profiles of temperatures and gas compositions in the reactor were also discussed.