Abstract: A new regional climatic model was developed and proof-tested by simulating the frontal rainfall, cyclonic rain and shower.The effect of different physical processes and different time step in the model was analyzed in order to choosing the approopriate experimental project. Using this model simulated the climatic effect of the change of land-use in Changjiang Delta area.Result s show that vegetation reducing and urban extending are main causes of the regional climate change.The range of seasonal temperature would increase and the humidity would decrease if the vegetation reduced.With the urban area extending the urban heat island effect would be intense also.