Why exactly did China decide to construct the Myanmar-China energy pipeline? While important for China's long-term energy strategy, very few studies have yet analyzed the project from the standpoint of China's domestic policy process. This paper fills the gap by illuminating the broader historical context and presenting how this pipeline fits into energy politics in China. The policy-making process is fleshed out by using the multiple streams framework (MSF). Analysis of this case using MSF shows that, first, local governments and scholars played a key role in facilitating the project, especially in raising the proposal to the government agenda. Second, a "policy window" remains an important element in China's energy policy decisions, in light of the China-Myanmar pipeline idea was not taken seriously in the 1990s when it was first proposed. Third, although this cross-border energy project is part of a national strategy of energy security, domestic political considerations such as promoting investment in China's underdeveloped southwest were also at work. These conclusions are useful for understanding not only the motivations behind such transboundary pipeline projects but also China's energy decisions at large.