Abstract: Abstract: Extending enterprises’ cyclic structure of investment built by Aghion, we analyze the cyclicality of R&D investment of enterprises in countries of different types, using panel data of 17022 enterprises in 97 countries and regions in the world during 2005-2014. The following conclusions are drawn. Firstly, not considering financial constraints, enterprises’ R&D investment of Chinese and developing countries is acyclic, while R&D investment of developed countries is counter-cyclical. Secondly, considering financial constraints, enterprises’ R&D investment of Chinese and of both developed and developing countries is counter-cyclical. The high financing constraints only turn R&D investment of Chinese and developing countries’ enterprises into pro-cyclical, and the high cash holding has no significant impact on the cyclicality of R&D investment of Chinese and developing countries’ enterprises. However, the high cash holding ensures counter-cyclical R&D investment in developed countries. Finally, R&D investment of Chinese and developing countries’ enterprises is counter-cyclical only during boom and acyclic during downturn because excessive liquidity stops R&D investment. R&D investment of developed countries is counter-cyclical during boom and downturn. The high financing constraints mainly increase R&D investment of Chinese enterprises during boom. High cash holdings don’t affect Chinese, developing and developed enterprises' R&D investment during downturn.