The primary aim of the thesis is to understand how to strengthen primary care in China, by looking at the effectiveness and functioning of a gatekeeping pilot, and more broadly at the history of the balance between hospitals and primary care providers. A secondary aim is to explore how multiple methods can be used to study a complex system-related issue. The thesis developed comprehensive metrics for structural and functional balance between primary and hospital care (1949-2013); developed a dynamic path dependence analytical framework to study the coevolution of the two sectors (1835-2013); used a difference-in-differences analysis to identify the impact of a gatekeeping pilot; and developed a qualitative systems analysis to understand the functioning of the pilot. The quantitative analysis suggested more patients did visit primary care facilities (increased by 38.7%) due to the pilot, but without obvious extra-spending. Evidence from the qualitative study suggested this seemed to be caused by patients visiting for referrals. The intended effects of gatekeeping in changing patients’ utilization pattern of care were made unattainable mainly by the existing weak conditions of primary care, feedback loops that further weakened primary care development regarding service capacity, human resources, and patient trust, as well as unintended consequences of other related policies. The dynamics between hospitals and primary care providers in the pilot were the contemporary manifestation of a long-term hospital-centric structure, where primary care providers were the de-professionalized antithesis of hospitals and relatively weakly institutionalized. The institutional complex was path-dependent and has gone through three cycles since 1835. The thesis has demonstrated the feasibility and value of using multiple analytical theories and research methods to address a complex health system issue. The findings of the study suggest the importance of building a strong primary care profession and the value of a political coalition for primary care strengthening.