Abstract: In order to study the impact of urbanization on local climate change in Chengdu, a series of numerical simulation experiments were carried out by using Weather Research and Forecasting model (WRF). Land use and soil categories were changed in the simulation to reflect the different situations. The effects of underlying surface changes on urbanization in Chengdu in summer and winter were discussed. The results show that Urbanization has a significant impact on the increase of surface temperature in summer. The sensitivity test shows that the underlying surface changing causes the expansion of the high temperature above 28℃ in summer in Chengdu and the expansion to the northeast and southwest, and it leads to the increase of surface temperature in surrounding areas of Chengdu. Chengdu is always cloudy and rainy in winter, so the solar radiation reaching the ground is greatly reduced than that in summer. The warming effect caused by urbanization is less significant than that in summer. Under the influence of urbanization, daily average precipitation is decreased in the upstream areas and increased in the downstream areas of the city. Urbanization increases the probability of extreme precipitation, in addition, the distribution of extreme precipitation is more concentrated to the downstream areas of the city.