This article briefly introduced the basic concept,theories of ecological footprint and its approaches to measure sustainable development.Based on the results of the report Ecological Footprints of Nations,global,national and regional ecological footprint were compared and analyzed It argued that the ecological footprints of individuals, region/cities, and nations unveil the sources of global ecological crisis and environmental problems,and now the global ecological footprint has severely exceeded the carrying capacity of the earth To achieve a sustainable future,the potential choices are (a)controlling population growth to decrease the ecological footprint of the growing population,(b)rebuilding environmental friendly lifestyle and consumption,(c)recurring to recycling and energy saving technology to improve the efficiency of resource development and utilization,and (d)protecting natural resources and improving their biological productivity.The possibilities and significance of the application of the ecological footprints in the Qinghai Tibet Plateau were also pointed out.