Abstract: The changing tendency of the performance of engine in its operational range can be directly showed in the engine characteristics map. An approach to represent universal performance characteristics using cubic polynomial interpolation was examined. The formulation of cubic polynomial interpolation and the remainder of cubic polynomial interpolation were deduced and the engine fuel consumption characteristics map was drawn by this method. Result shows that it can exactly reflect the performance of engine to use cubic polynomial to draw engine fuel consumption characteristics map. This method can also be used to draw the engine emission and other characteristics map. It provides a useful method for drawing the engine performance characteristics map.