China's emissions trading scheme (C-ETS) is a market-based approach to internalize the emission reduction costs of polluting enterprises. Since 2013, eight provinces and cities in China have launched their pilot ETS to provide the national one in July 2021, with experiences in regulation, implementation, monitoring, and feedback from participating enterprises. This thesis looks into the renewable energy companies that are companies whose main business is generating renewable energies, and adopts the difference-in-difference (DID) approach and propensity score matching method (PSM) to evaluate the impact of the pilot ETS policy on the financial performance of the enterprises. This study finds that the implementation of ETS has not shown a boost to the financial performances of renewable energy companies due to the design of the scheme, the low price level and the postponement of carbon credit projects. Hence, to enhance the financial performance of these companies, the government needs to refine the current carbon trading scheme by involving more participants, adopting stricter allowance allocation mechanism, resuming carbon offset programs and ensure that it functions in favor of sustainable growth for the renewable sector.