Abstract: Land use and land cover change(LUCC) is a major variable affecting the long-term hydrological processes. To quantify simulate the impact of land use cover change on hydrological processes in large basins, a large scale distributed hydrological model was developed. The hydrological effects of potential land use change scenarios are evaluated by using the distributed hydrological model based on theoretical scenarios. The results indicated that the output of the model successfully reveals the response character of ratios among ET, surface runoff, base flow under given precipitation at HRUs to basin scales. The evapotranspiration, surface runoff, groundwater flow and water yield were affected by the land use change scenarios in different magnitudes. Overall, changes of land use and land cover have significant impacts on runoff patterns at the watershed scale in terms of both the total water yield(i.e., sum of groundwater flow, surface runoff, and interflow) and the spatial distribution of runoff. The changes in runoff distribution were opposite within the two land use scenarios with the emphasis on forest or agriculture. The base flow was the most affected component in the hydrological cycle, which has a decrease of 15.3 percent in the forest-prone landscape scenario. Whereas, the surface runoff has a decrease of 5.2 percent. All scenarios show not significant impacts on the evapotranspiration and the general water yield, which were limited to the 1.2% and 0.7%. Thus, the different runoff patterns associated with each land use scenario imply the potential effect on flood or drought mitigation policy. The rational spatial planning can be conducted based on the hydrological impacts from HRUs to sub-basins.