Abstract:Effect of international collaboration research depends on many factors, among which disciplinary positions of collaboration partners are critical. Based on publications indexed in the Web of Science and funded by the National Natural Science Foundation of China (NSFC), we studied the effects of international collaboration of China with G7 countries in terms of highly cited publications and average citations. The USA is the leading partner of China, followed by Canada, Japan, the UK, Germany and France. Italy has least collaborations with China. In raising impact (i.e., percentage of highly cited publications and average citations) of international collaboration, the effects of NSFC are more obvious in mathematics, chemistry and chemical engineering, physics and materials sciences, although such effects are dependent on countries. The NSFC’s impact-raising effect is more apparent in areas in which China is relatively strong. In weak areas of China, such as environment and ecology, neuroscience and behavioral science, microbiology and genetics, as well as clinical medicine, the impact-raising effect of NSFC for international collaboration is not as good as those of unfunded. In the end, policy suggestions are provided.