We have incorporated a single-layer urban canopy model into the Noah Land Surface Model (Noah-LSM) and coupled it with the Weather Research and Forecasting (WRF) model. This relatively simple single-layer urban model is able to parameterize the urban building geometry (building height, road width, etc.) and explicitly calculate the surface temperature at roof top, road, and wall. It takes the shortwave and longwave radiation trapping effects and the reduction of solar radiation by building shadows into account. Therefore, this couple system is hoped to improve surface energy budget, in particular, in urban area. We will present the preliminary results that we employed this coupled system to the greater Houston area to investigate impacts of urban on the mesoscale circulation and on the development of the boundary wind, temperature and humidity structure.