Assessing the response characteristics of ecosystems under climate change is critical to improve ecosystem services and protect ecological environments. Existing climate change assessment models are mostly based on large-scale (global and regional) research, and are not suitable for smaller geographical scales (local). Based on the data from 2015, this study improved the Comprehensive Sequential Classification System (CSCS) using local characteristics, simulated the natural vegetation distribution, and analyzed the spatial and temporal changes in vegetation coverage and soil conservation services in the Three-Rivers region under different future greenhouse gas emission patterns. The results indicated the following: ①Under different emission scenarios in 2080, increased precipitation and temperature mainly occurred in the growing season (from May to September) and in semi-humid areas, and the largest increases occurred under the high-emission scenario (42.21 mm and 4.93 ℃). ②The potential natural vegetation type was mainly transformed from grassland to forest, and increases in vegetation coverage and soil conservation services followed a descending trend from northwest to southeast under the three scenarios, which is consistent with the trend observed for water-heat conditions. The highest increases occurred under the high emission scenario and the lowest increases under the low emission scenario. ③Accuracy was improved by 24% when the CSCS was revised using local glacial bare land succession characteristics and multi-year NPP (Net Primary Production). These results provided necessary methods for assessing the response characteristics of ecosystems under climate change at smaller geographical scales.