Abstract:The paper provides an in-depth discussion on the classification of ancillary services in the new power system and their market-based procurement mechanisms. As China accelerates the construction of a new power system dominated by renewable energy, various market participants are required to provide a wider range and more diversified ancillary services to ensure the stable operation of the power grid, the quality of electricity supply, and the absorption of clean energy. The paper classifies the ancillary services in the new power system into three categories: "clean energy consumption promotion", "power quality", and "system security and stability". It describes the characteristics and challenges of market-based procurement and coordination mechanisms for each type of ancillary service, and analyzes the allocation and compensation mechanisms for these services. Finally, the paper explores future research directions for the market-based procurement mechanisms of electricity and ancillary services. The research outcomes offer valuable insights for the design of market mechanisms for ancillary services in the new power system.