Hydrogen is playing an increasingly important role in China's energy and climate policy, with significant implications for the development of a global hydrogen industry. However, China's approach to the regulation of hydrogen, and, in particular, the role of local authorities in promoting hydrogen refuelling stations and fuel cell vehicles, has so far received limited scholarly attention. This article aims to contribute to the literature on hydrogen regulation and to the transnational environmental law scholarship on decentralization by examining how China promotes hydrogen at the national and local levels. The case of China shows how, in jurisdictions with a sufficient degree of decentralization, local initiatives can play a key role in driving the development of hydrogen. By testing different approaches to hydrogen regulation, local experimentation helps to manage the uncertainties associated with this new energy source. At the same time, China's experience confirms the ‘environmental federalism’ theory on the importance of regulatory harmonization to reduce transaction costs and local protectionism. As the Chinese government develops its national regulatory approach on hydrogen, it has the opportunity to take into account both local and international experience and engage with other major economies in an effort to promote an internationally harmonized regulatory landscape.