Taking Bengbu watershed of Huaihe basin as study area, the paper quantitatively assessed hydrological effects of land use and land cover change,and the quantitative relation between basin runoff and main types of vegetation change by use of three historical cover scenarios including 1700, 1800 and 2000.The results show that CLHM model can be used to simulate the flow process of the Huaihe basin and has good applicability in the area;the main type of vegetation change in the three cover scenarios are forest to farmland or grassland and grassland to farmland.The change result in the reduction of 6.5% of total evaporation and the increase of 6.1% of average outlet flow; under the condition of extreme vegetation, the value of annual average evaporation from more to less is forest, grassland and farmland;the effect of forest on runoff process is mainly reflected on flood peak,and forest has the effect of reducing peak; by analyzing the relationship between the type of vegetation change and mean annual runoff of the Bengbu watershed, forest converting to grassland and farmland are the main factors of effecting the hydrologic process and water resource distribution in Huaihe basin in near 400 years. Therefore, it is important and significant for efficient utilization of water resources to reasonably plan land use pattern.