The Main Board traces its origins to 1986. It evolved and grew along with the shareholding system reform of state-owned enterprises (SOEs) and in response to their development needs. The Main Board underwent three stages of development: preparation and establishment, adjustment and rapid development, and deepening and improvement. Over the years, the Main Board has witnessed continuous improvement in quality thanks to the concerted efforts of market participants. Supported by enhanced financing function and improved corporate governance structures of issuers, the Main Board has continuously expanded its capacity to serve the real economy. 

Underpinned by modern technology, The Main Board has evolved into a nationwide securities market over the past three decades and has become a vital financing channel for major enterprises. Many listed companies have grown into global leaders in their respective industries.

In February 2021, upon approval by the State Council and the CSRC, the SZSE initiated preparations for the merger of the Main Board and the SME Board. Guided by the principle of "Two Unifications and Four Retainments", the rules, operations, and supervision frameworks of the two boards were unified, while issuance and listing requirements, investor eligibility, trading mechanisms, security codes and stock short names remained unchanged. The merger took effect in April 2021, forming a two-tier structure comprising the Main Board and the ChiNext Market, which is more streamlined, and clearly defined.

As of September 2026, a total of 1,499 companies were listed on the Main Board with a total market capitalization of RMB 24.6 trillion.