BACKGROUND: China has launched methadone maintenance treatment (MMT) and needle and syringe exchange programmes (NSEP) as part of the country's HIV prevention strategy amongst injection drug users. MMT is expanding, with backing from multiple government ministries, however, NSEP have received less political support and funding. METHODS: Semi-structured, serial interviews were conducted with key informants, knowledgeable about China's harm reduction policies. Concurrent content analysis allowed for revision of the interview guide throughout the data collection process. This was combined with a systematic analysis of official government policy documents on NSEP and MMT, including white papers, legal documents, and policy statements. FINDINGS: Early consensus between public security and public health sectors regarding methadone's dual use in HIV prevention as well as method of drug control created broad institutional support for MMT programmes amongst policy makers. In contrast, NSEP were seen as satisfying only the HIV prevention goals of the public health sector, and were perceived as condoning illicit drug use. Furthermore, NSEP's roots in China, as an experimental collaboration with international groups, created suspicion regarding its role in China's drug control policy. NSEP and MMT's distinct paths to policy development are reflected in the complex and occasionally contradictory nature of China's harm reduction strategy. CONCLUSIONS: These discrepancies highlight the need for a more politically sustainable and comprehensive integration of harm reduction projects. Recommendations include improved evaluation methods for NESP, NSEP-MMT cross-referral system, and stronger NSEP advocacy within the non-profit and public health sectors.