Abstract: Plant carbon use efficiency（CUEa） refers to the ratio of net primary productivity to total primary productivity, which is an important parameter for the allocation of plant photosynthetic utilization. It not only reflects the ability of vegetation ecosystems to convert air CO₂ into biomass and carbon sequestration development potential, but also reflects the impact of photosynthesis on vegetation productivity, and is the whole process of plant carbon source or carbon sink. Carbon use efficiency（CUEe） is a key parameter for comparing material cycle gaps in different ecosystems. Understanding the ecosystem CUEe can better understand the carbon sources and sinks of terrestrial ecosystems, and the ecosystem CUEe predicts global change and human impacts, and has an important impact on the forest carbon cycle. In this paper, the research progress of plant carbon use efficiency was summarized by reviewing, sorting and summarizing the relevant literature on the influencing factors of carbon use efficiency, mainly including: the relationship between biological and abiotic factors（temperature, altitude, rainfall, light, human factors, etc.）, and their interaction and interconnection affect the change of CUEa. This paper also reviewed the current carbon utilization efficiency measurement methods at home and abroad, discussed the principles, technologies, advantages, disadvantages and scope of application of each measurement method, and looked forward to the future of CUEa research.