Abstract:Scientific and technological innovation cooperation is the core content of the "Belt and Road Through joint R D, technology transfer and achievement sharing, the cooperation brings technology spillover, promotes industrial transfer, and eventually drives the development of related industries, and effectively promotes the upgrading of regional industries. Core cities, as the important junctions of "Belt and Road pace-setter and main force of scientific and technological innovation cooperation. Based on the panel data of 281 cities in Mainland China from 2008 to 2017, this paper studied the effect of the “Belt and Road” scientific and technological innovation cooperation on industrial upgrading of the core cities along the Belt and Road by using the methods of propensity score matching (PSM) and difference-in-difference (DID). The conclusions show that: The cooperation has a significant effect on the industrial structure rationality of the core city along the Belt and Road. However, it does not contribute to the high-class effect of the industrial structure. Besides, compare with the coastal core cities, the cooperation has a stronger effect on the industrial upgrading of inland core cities. After identifying the policy mechanisms,we find that foreign trade,per-capita income and fiscal expenditure enhance the influence of the “Belt and Road” scientific innovation cooperation on the rationality level of the industrial structure. In the meantime, financial development promotes the high-class effect of the industrial structure.