Abstract: G8 summit was held in 2013 and the countries signed the Open Data Charter, which became a landmark event for global open data, as well as the important basis of open data research in the world. The arrival of big data has sped up the opening degree of data in various fields. United States, Britain and other developed countries led the global data open, while the study of G8 countries' open data policies was of great importance for building China's open data policy. This paper chose the open data policies of G8 countries' typical authority polices, to construct the comparative research framework of big data, and summarized the commonness, difference and trend, and finally put forward some suggestions on the enlightenment to China.

Key words: open data