Ecological footprint is quantificational evaluation index of the status of ecological system appropriation by human beings. It is a hotspot index for quantificational estimation of sustainable development. Nowadays, the ecological footprint is increasing with the increase of population and it's consumption. The research categories of ecological footprint include the carrying capacity of the Earth, the sustainable maintenance of Earth's ecosystem and the sustainable development of human beings, and so on. The research status and trends of the ecological footprint was quantificationally analyzed based on bibliometrical methods. The references about ecological footprint were indexed in the ISI Web of Knowledge. The analysis indicates that the United States has the maximum papers. China papers mainly published during 2004 to 2006 and the important author organizations are Chinese Academy of Sciences, Hongkong University and Lanzhou University. The references of ecological footprint relate to case analysis, theory and methodologies. Most references focus on the temporal dynamic measurements and international comparison. The methodologies mainly include input-output method, compound method, component method. The input-output method is the most important method.