By constructing global multi-regional input-output (MRIO) table based on GTAP8.0 database, production-based and consumption-based CO2 emissions of China and the United States were calculated in this paper, as well as CO2 emissions embodied in exports of China and the U.S and the industry distribution. The results showed that the consumption-based CO2 emissions of China in 2004 and 2007 were 428 Mt and 522 Mt lower than production-based CO2 emissions. To the United States, the consumption-based CO2 emissions in 2004 and 2007 were 272 Mt and 221 Mt higher than production-based CO2 emissions. China is a net exporter of CO2 emission while the U.S. is a net importer of CO2 emission embodied in international trade. Compared to the United States, the CO2 emissions embodied in China's exports accounted for higher proportion than that of the U.S. in total domestic CO2 emissions, while the emissions in imports accounted for lower proportion than that of the U.S. in total domestic CO2 emissions.