This study proposed a novel way for global greenhouse gas reduction through reusing China's waste oil to produce biofuels. Life cycle greenhouse gas mitigation potential of aviation bio-kerosene and biodiesel derived from China's waste oil in 2010 was equivalent to approximately 28.8% and 14.7% of mitigation achievements on fossil-based CO2 emissions by Annex B countries of the Kyoto Protocol in the period of 1990-2008, respectively. China's potential of producing biodiesel from waste oil in 2010 was equivalent to approximately 7.4% of China's fossil-based diesel usage in terms of energy. Potential of aviation bio-kerosene derived from waste oil could provide about 43.5% of China's aviation fuel demand in terms of energy. Sectors key to waste oil generation are identified from both production and consumption perspectives. Measures such as technology innovation, government supervision for waste oil collection and financial subsidies should be introduced to solve bottlenecks. (C) 2012 Elsevier Ltd. All rights reserved.