Abstract: The construction of a high percentage renewable energy power system is an inevitable choice to cope with climate change and achieve the “dual carbon” goals. Flexibility resources that can smooth the variability of renewable energies play an increasingly important role in the power system. However, China’s electricity market is currently in its infancy, lacking market mechanisms to accommodate the participation of these new flexible resources, making it difficult to give full play to its role. To this end, this paper outlined the characteristics, classification and current development scale of new flexibility resources represented by demand response and virtual power plants, and presented the current status of mechanisms for new flexibility resources to participate in the electricity market, using the US, UK, German and Australian electricity markets as examples. This paper analyzed the current status of participation of electrochemical energy storage, demand response and virtual power plants in typical foreign electricity markets in terms of the scope of participating entities, market entry threshold, different pricing mechanisms in energy market, capacity market and ancillary service market, types of services provided, and settlement methods. And on the basis of describing the policy objectives, current market mechanisms of new flexibility resources in the electricity market of China, and the analysis results of typical foreign electricity markets, the opportunities and challenges for further improving the participation mechanism of new flexibility resources in the electricity market in China were pointed out. The analysis shows that China should clarify the status of market subjects of new flexibility resources in standards and specifications, adjust the market access threshold according to the maturity of flexibility resources’ participation in the market according to local conditions and time, and promote pricing and settlement through the market mechanism, while continuously improving the market clearing model. So as to give full play to market mechanism’s ability to integrate and optimize the allocation of flexibility resources, promote the participation of new flexibility resources in the electricity market, and improve the flexibility of the power system.