Abstract: Building a national unified market is a key strategy for establishing a high-level socialist market economy and advancing Chinese modernization. This research systematically examines its internal logic, real-world constraints, and distinctive functions. Studies indicate that the development of a national unified market is grounded in clear historical logic, urgent practical logic, and rigorous theoretical logic. As a large transitional developing country, China’s market exhibits a series of typical characteristics—such as enormous scale yet severe fragmentation, rich hierarchies yet complex structures—and its construction process consistently involves trade-offs among multiple deep-seated constraints, including industrial policy versus competition policy, central-local relations, and openness versus security. Further analysis reveals that the national unified market plays an irreplaceable role in coordinating the new dual-circulation development pattern: by deepening the division of labor and promoting the optimal allocation of factors, it effectively aligns incremental and stock resources, quality and quantity, new and old growth drivers, aggregate supply and aggregate demand, as well as effective markets and proactive government, thereby providing solid institutional support and market foundations for smoothing national economic circulation, shaping new development advantages, and addressing internal and external risks and challenges.

Key words: national unified market, dual circulation, economic security, global value chain, interprovincial trade