The preferential tax policy is an important policy for non-profit scientific research institutions in China. First, the basic theory and content of the preferential tax policy for non-profit scientific research institutions are described.Then by taking U.S., Germany, and Australia as the examples the preferential tax policy in developed countries is analyzed.Their preferential tax policy includes the qualifying certification for the institutions and the preferential tax for the institutions themselves and their donators.In the end, the barrier and mode of the preferential tax policy for non-profit scientific research institutions in China are discussed.