By using nonhydrostatic WRF model, we did highresolution numerical simulation on the landfall process of Typhoon Morakot in this paper. The simulation, is triplenested with the highest resolution of 2 km, integrated 72 h (3 d). We also carried out careful comparison between the simulation result and the observation data. The result shows that WRF model successfully simulates the development and landing process of Typhoon Morakot, and the simulated path is quite consistent with the observation. At the same time, the model also successfully shows the evolving process and the feature of main radar echoes in the whole simulating period. Furthermore, with the highresolution simulation data we carried out diagnostic analysis on the landing process of Typhoon Morakot with the generalized waveactivity density M. The result shows that the abnormal values of wave action density M always cover the observed precipitation regions horizontal distribution and temporal evolution are quite similar.