Large-scale eco-environmental vulnerability assessment is conducive to a comprehensive understanding of the quality of ecological environment, which can help accurately capture the ecologically vulnerable areas. Under climate change scenarios, this paper predicted the eco-environmental vulnerability for future mainland China at the county level, and analyzed its trends under the four scenarios. Results shows that areas with higher levels of vulnerability are mainly located in the western China and at the junction of south provinces, while the eco-environmental vulnerability of the eastern and southern coastal areas is relatively low. In terms of temporal trends, the NECR and MGR have the most stable eco-environmental vulnerability, while the eco-environmental vulnerability in the LPR, SWCR and GXR shows an obviously increasing trend under the scenario with high radiative forcing level. The most obvious increase in eco-environmental vulnerability is identified in the North China Plain under RCP 8.5. By comparison, the increment in vulnerability grades during 2020s-2090s is significantly higher than that of the period 2020s-2050s, especially under RCP 8.5 scenario. The trends of eco-environmental vulnerability show upward tendency overall, and the northwestern and southeastern regions have the biggest changes in eco-environmental vulnerability, especially under the high emission scenario.