Facing the issues of global climate change, the European Union introduced the mandatory global carbon emissions trading mechanism under the Kyoto protocol model. In the Copenhagen Conference, China has promised that CO2 emissions per GDP in 2020 would decrease by 40% to 45% than that in 2005. In order to fulfill this goal of reducing GHG emissions, China has carried out National Carbon Emissions Trading (CET) in 2018. In view of electric power industry, facing the requirements of emission-reduction and green economy, optimizing the electric structure is around the corner. And developing renewable energy has become one of the most effective ways. In the "thirteenth five-year" period, China has implemented Renewable Portfolio Standard (RPS) to promote the uptake of renewable energy, and it has derived National Tradable Green Certificates (TGC) market in 2018. However, when TGC trading meets CET in the electricity market, what will the electric structure turn to be? Can we achieve the goal of CO2 emissions-reduction? Will there be policy redundancy between TGC and CET? How could we design these two systems? They are interesting questions, and also the key points this study addresses.Firstly, we build the equilibrium model of TGC market, CET market and electricity market. Secondly, we analyze the internal connection of these three markets and relationships between TGC price, electricity price and carbon price. Based on this, we further construct the system dynamics model of three markets, and simulate the dual effects of implementing TGC and CET systems in the electric market. Finally, we can see whether the government could meet the goals of electric structure optimization and CO2 emission-reduction.The conclusions are as follows:(1) The increase of Renewable Portfolio Standard (RPS) and carbon price is advantageous to the expansion of green electricity. But it doesn't mean that the higher the carbon price and the higher the quota, the better. (2) Implementing TGC and CET could effectively realize the electric structure optimization. The proportion of renewable energy power generation is expected to achieve the goal of ‘renewable energy thirteenth five-year development planning’ by 2020 (Goal: 680 million kilowatts of renewable energy power generation capacity, 1.9 trillion kWh, 27% of all electricity generated). (3) The CO2 emissions in the electric power industry will be controlled, effectively promoting the realization of national CO2 emissions-reduction target (Target: CO2 emissions per GDP should decrease to 1.6298 tonnes/10000 RMB by 2020). (4) Meanwhile, TGC system and CET system are redundant for traditional energy enterprises in China. Finally, we propose policy recommendations on the mechanism design and implementation for these two systems
