We discuss the factors influencing palletization. A heuristic has been developed to cope with the three-dimensional palletization problem in which boxes have different base dimensions and can be grouped by same height. The layered-pallet-loading technique has been applied to the proposed heuristic. Brown's Linear Equation Approach has been modified and incorporated in the proposed heuristic to determine the optimal layout for each layer. Then a stability analysis is conducted to determine the optimum layer order and layout. The application of the proposed heuristic is illustrated by an example.