Abstract: Since the reform and opening up， the process of development of the thought of the Communist Party of China on the construction of an ecological civilization system has gone through stages of preliminary formation， deepened development， and enrichment and perfection. In the preliminary formation stage，the CPC Central Committee put forward the ideas of legalizing environmental protection and strengthening the construction of environmental protection systems. In the deepened development stage，the CPC Central Committee has become increasingly aware of the importance of improving laws and policies that are conducive to energy conservation and ecological environment protection. The understanding of environmental protection system construction is becoming more comprehensive. In the enrichment and perfection stage， the CPC Central Committee has put forward the ideas of deepening the reform of the ecological civilization system and accelerating the construction of an ecological civilization system. The top-level design of China's ecological civilization system is driven to maturity.

Key words: CPC, ecological civilization, construction of ecological civilization system, environmental protection system