This study traces the transnational interactions that contributed to introducing the low-carbon economy agenda into Chinese policymaking. A microprocessual two-level analysis (outside-in as well as inside-access) is employed to analyse transnational and domestic exchanges. The study provides evidence that low-carbon agenda-setting – introduced by transnational actors, backed by foreign funding, promoted by policy entrepreneurs from domestic research institutes, propelled by top-level attention, but only gradually and cautiously adopted by the government bureaucracy – can be considered a case of effective transnational diffusion based on converging perceptions of novel policy challenges and options. Opinion leaders and policy-brokers from the government-linked scientific community functioned as effective access points to the Chinese government’s policy agenda.