In this paper, an endogenous energy efficiency improvement (EEEI) mechanism is introduced into the Chinese economy-energy-environment integrated model, which is an extended version of the global integrated assessment model ( E3METL) . The impact of EEEI on the growth of CO2 emissions is explored by means of factorization, and the evolution of carbon reduction contributions of the corresponding influencing factor is examined in the presence of carbon controls. It is found that: 1) Both carbon intensity and energy intensity play a positive role in the growth of carbon emissions, while the per capital income and population factor negatively affects the carbon path; 2) In the early stages of carbon control, EEEI is the largest contributor to the cutting of CO2 emissions; the situation changes in the later stages, and the development of non-carbon technologies acts as the largest contributor instead. Thus, it is of great importance to master the dynamic laws and features of the evolution of carbon reduction factors. For example, the government should adjust the direction and intensity of its macro-driven policies in time; while enterprises have to determine their investment orientation of carbon-reducing technologies duly, so as to achieve their carbon reduction goals more cost-effectively.