三江源区作为国家生态安全“两屏三带”战略格局的重要组成，其生态安全状况对全国乃至东南亚地区都有重要影响。本文以遥感参数反演和模型计算数据，结合实地调查和社会经济统计等数据，采用层次分析法和指标体系法，对三江源区生态承载力和生态安全状况进行了评价，并根据短板效应分析了限制三江源区生态承载力和生态安全的因素。结果表明：（1）三江源区生态承载力处于中等水平，空间上呈现出由东南向西北逐渐减少的格局；（2）限制三江源区生态承载力的因素主要是水源涵养量、初级生产力、地表水水质、植被覆盖度以及受威胁动物数量等；（3）三江源区生态安全状况基本处于濒危到较安全之间；（4）三江源区西部欠发达地区生态承载力水平较低，相对落后的经济水平限制了环境保护的力度和水平；而东部较发达地区，人口增长快但文化素质不足，难以满足社会经济快

速发展与生态安全保护的双重需求。

The Sanjiangyuan Region is an important component of the national ecological security strategic structure —“Two Screens & Three Zones”—in China, and its ecological security situation has a significant impact on China and even the region of Southeast Asia. Combined with information from field investigations and socioeconomic statistics, this paper adopts related methods of remote sensing parameter inversion, model simulation as well as the analytic hierarchy process and comprehensive index system to evaluate the ecological carrying capacity and ecological security situation of the Three River Sources Region. The results show: (1) the ecological carrying capacity of the Three River Sources Region is at the medium level and presents a pattern of decrease from southeast to northwest; (2) the major constraint factors on the ecological carrying capacity are water conservation quantity, NPP, surface water quality, vegetation coverage and the amount of threatened animals in the Three River Sources Region; (3) the general ecological security of the Three River Sources Region ranges from danger to arelatively safe situation; (4) the ecological carrying capacity is relatively low in the western underdeveloped region where the economic backwardness reduces the degree of local environmental protection effort; and meanwhile, the rapid population growth and the low cultural quality in more developed eastern region also causes conflict between economic development and environmental protection.