The construction of land use change model is an important means to deeply understand the cause and process of land use change, forecast the future development trend and analyze its environmental influence. In order to reveal the evolution law of the basin Land Use/Cover Change (LUCC) under the changing situation, based on Conversion of Land Use and its Effects at Small Region Extent model (CLUE-S), two scenarios of natural growth and ecological protection are set up with Fuxian Lake located in Yunnan province, China, as the research area to simulate the LUCC of the basin in 2020. The results show that the CLUE-S model has high reliability to simulate the future Land Use/Land Cover (LULC) change in the basin scale and the high simulation accuracy as a whole, and the Kappa coefficient is all above 0.8; under the scenario of natural change, the ecological lands like forest land, cultivated land, grassland and garden land are decreasing, in which the decrease of forest land is the largest, while the non-ecological lands such as construction piling, building area, structure and road is increasing, and the increase of construction piling is the largest. It is bound to pose a serious threat to the ecological security of the basin; under the scenario of ecological protection, the increase of forest land and water area is the largest, while the cultivated land, grassland, construction piling and garden land are greatly reduced. It shows that the quantity of ecological land increases obviously while the quantity of construction land, planting land and other land which play a restriction on ecological environment protection is decreasing, which will be beneficial to the ecological environment protection of the river basin.