Abstract: Carbon footprint of electricity is a measurement of the amount of life cycle CO₂ emission associated with the whole process of power generation. From the perspective of global carbon cycle,  the characteristics of carbon emission from different power generations are partially the land cover’s carbon sequestration capacity. This paper calculated the average carbon footprint equivalent of global electricity, i.e., the life cycle carbon footprint for per unit of electricity consumed, and analyzed the composition of  carbon footprint of global electricity and its changes in 2000-2008, based on the synthesis of large amount of investigation data. The worldaverage global carbon footprint equivalents of coal, oil, and natural gas used for thermal electricity generation, and of hydroelectricity and nuclear electricity were 131.3×10^-6, 95.8×10^-6, 56.6×10^-6, 38.8×10^-6, 1.9×10^-6 hm²·(kW·h)^-1, respectively, indicating that the environmental impact of thermal electricity, especially coal-based electricity, was significantly greater than that of hydroelectricity and nuclear electricity. From 2000 to 2008, the carbon footprint of global electricity increased from 730.7×10⁶ hm² to 1101.8×10⁶ hm², in which, the proportion of thermal electricity increased from 60.0% to 68.1%, in particular coal replaced oil to be the largest source of the carbon footprint of thermal electricity, while the proportion of hydroelectricity and nuclear electricity fell to 30.7% and 1.3%, respectively. Overall, the structure of global electricity revealed a trend towards deterioration, for the worldaverage carbon emission coefficient of electricity increased from 265.8×10^-3 kg·(kW·h)^-1 in 2000 to 315.4×10^-3 kg·(kW·h)^-1 in 2008. The results highlight the need for reducing the use of thermal electricity, especially coalbased electricity, which largely determines the intensity and scale of carbon emission from power generation.