The Communist Party of China is the most important core subject of government ecological responsibility investigation, which is not only the meaning of adhering to the Party’s leadership, but also the internal requirements of the Party’s governance, with unique institutional value, practical value and theoretical value. In China’s current national governance system and related rules and practices, the functional system for the Party to fulfill the government’s ecological responsibility in the new era has been preliminarily positioned from the aspects of the subject, object, content (reason), and approach (method) of accountability. However, there are still inherent limitations of “same-person accountability”, the vague definition of the Party and government responsibilities, the relative lack of accountability within the Party, and the lack of coordination between the Party and the cooperative accountability mechanism. Strengthening and optimizing the performance of the Party’s function of investigating the government’s ecological responsibility must be guided by Xi Jinping’s new era of socialism with Chinese characteristics. We must adhere to the Party’s overall leadership, clear boundaries of responsibilities, multiple responsibilities, multi-subject cooperation, and ecological responsibility, constantly improve heterogeneous accountability to enhance the power and effectiveness of responsibility, improve the accountability system to promote the pursuit of fairness and efficiency, and enhance the ability to pursue responsibility to optimize the role and effectiveness of accountability.