Abstract: Taking typhoon 9414 as an example, the effect of asymmetric diabatic heating on tropical cyclone motion is analysed using the mesoscale model (MM4). The calculated results show that the typhoon track prediction and precipitation forecast are improved obviously considering the asymmetric diabatic heating. If the initial asymmetric moisture field for the typhoon area is also included, the improvement will be more obviously. In order to put in operation, the diabatic heating calculating scheme of several typical spiral structures is constructed and led into the thrmodynamic process of the model. The results show that when the spiral structure which is similar to the real distribution of cloud system is selected, the accuracy of typhoon track prediction could be improved.