Abstract: The clean energy innovation is for the purposes of addressing climate change, energy crisis and environmental pollution. The patent system reform is the system adjustment for the clean energy innovation. The U.S. has carried out a series of patent reforms, including American Invents Act, to speed up its patent deployment and extend its international competitiveness in the field of clean energies. China's patent situation in clean energy industry is limited to the domestic innovation and lacks international innovations, whilst patents are treated more as commercial means but not for the purpose of promoting technological innovation. By analyzing the U.S. patent regime reform in response to clean energy innovation, this study aims at providing some reference to China's clean energy research and practice.