Abstract: In this article, numerical experiments of rainfall associated with T0216 (Silaku) are carried out using MM5 numerical model. And the simulations are successful. The simulating precipitation cell intensity and position, precipitation distribution all match with the observations well. For a good understanding of the precipitation mechanism associated with the tropical cyclone, we also carry out many other experiments. The results indicate:(1) When the cold air invades the external part of the tropical cyclone, the precipitation far off the tropical cyclone center and in the inverse trough increases in great quantum. When invading the vicinity of the typhoon center, the cold air reduces the tropical cyclone center intensity, the precipitation near the center decreases prominently, while the precipitation outside the tropical cyclone and in the inverse trough increases notablely. (2) The orographic effect augments the rainfall over the upwind slopes of the mountains, precipitation cell intensity and the precipitation near the tropical cyclone center. It abates the rainfall over the downwind slopes of the mountains. So the orograohic effect makes the precipitation distribution more asymmetric.(3) The humidity field of landmass and region near the sea shore has a great impact on the rainfall associated with tropical cyclone.The results mentioned above will play a valuable role in forecasting the rainfall during a tropical cyclone process.