Abstract: In recent years, the Chinese government has introduced a series of policies to attract more and more scientists to return to China. It is worth discussing how to balance international and local collaboration among returned researchers. This study takes the scientists who returned to China from 2007 to 2016 as an example and analyzes the trend of international cooperation and local collaboration after the flow of scientists to China over time. Further, we explore the reasons for the evolution of the scientific research collaboration patterns. This study provides three findings. First, when researchers move to China, they significantly increase local collaboration while maintaining international cooperation. Second, researchers who returned later prefer international collaboration more than those who returned earlier. Last but not least, researchers who moved to China quickly became principal investigators (PI).

Key words: Growth law of scientists, Returned scientists, Scientific collaboration patterns, International collaboration, Local collaboration