Abstract: China faces multiple opportunities such as rapid development of the renewable energy source （RES）,the reform of the electricity market,and the steady progress of carbon market construction,and market-oriented mechanisms will scientifically guide rational planning and effective investment of RES.Although the electricity market and carbon market operate in a separate fashion,their clearing outcome is tightly coupled and jointly affects the operation and investment planning models for market participants.Under the background of electricity-carbon coupled market,a bi-level optimization model of RES investment planning is proposed,targeted to maximize the hosting capacity of RES,while ensuring its investment cost recovery.First,based on dynamic carbon emission characteristics,the electricity-carbon coupled quotation of conventional units is derived,and the power spot market mechanism considering the influence of carbon quota trading is proposed.Then,a bi-level optimization model of RES investment planning is established under the framework of“investment-operation”.The upper-layer model maximizes the investment capacity of RES and determines its capacity and location under the premise of recovering the investment cost.The lower-layer model simulates the clearing process of the electricity spot market and the Chinese certified emission reduction market respectively to provide corresponding price signals to the investment decisions of RES generators in the upper-layer model.The bi-level optimization model is transformed into mixed-integer linear programming for the solution by the optimization condition and linearization method.Finally,the effectiveness of the proposed method is verified by a simulation case,and the influence of different factors such as carbon market trading,network capacity and energy storage on the optimal investment capacity of RES is discussed.