The change of water conservation function has an important impact on the ecological hydrology of the basin and the safety of water supply, A stable and good water conservation function is the foundation of the high-quality development of the regional economy and society. Based on the InVEST water yield module, the water conservation model and the pixel-by-pixel linear fitting, we simulated the temporal and spatial variation of water conservation in Qinling Mountains and the north and south slopes of Qinling Mountains from 1981 to 2015, analyzed the response of water conservation to climate change, and explored the evolution trend of water conservation under the background of climate fluctuation. The results show that: (1) The water conservation in Qinling Mountains showed a declining trend over the past 35 years, with an annual change rate of -1.44 mm, and the declining trend of water conservation on the northern slope of Qinling Mountains was greater than that on the southern slope of Qinling Mountains. (2) In recent 35 years, the trend of spatial changes in water conservation in Qinling Mountains had spatial heterogeneity, except for the upper reaches of the Yudai River, the upper reaches of the Muma River and the upper reaches of the Chu River on the suoth bank of the Han River, where the average annual water conservation increased slightly, the other river basins showed an overall downward trend, and the downward trend of water conservation in the central Qinling Mountains was greater than that in the peripheral regions. (3) Precipitation reduction and increased reference evapotranspiration were the main factors affecting the decrease of water conservation function in Qinling Mountains. Under the background of warm and dry climate, the water conservation of Qinling Mountains may further decline. Mastering the temporal and spatial variation characteristics of regional water conservation function has guiding significance for scientific assessment of regional water security, prediction of future water resources change trend and water resources management under the background of climate change.