Abstract: Soil carbon (C) pool is the largest organic C pool in terrestrial ecosystems. Plant-derived belowground C input is crucial in the process of soil organic C (SOC) sequestration. However, the current research in this direction is not systematic enough and lacks integration and summary. This paper used VOSviewer and CiteSpace information visualization software to conduct quantitative analyze and summarize the literature on the contribution of plant belowground C input to SOC from 1990 to 2023 in the Web of Science (WOS) core collection database, and to analyze the research trends. The results indicated that the study of the contribution of plant belowground C input to SOC showed a steady upward trend with time. From the perspective of the main body of the publication, the number of publications in China and the United States accounts for 65.16% of the total amount of documents. The Chinese Academy of Sciences was the scientific research institution with the largest number of publications, and the author Kuzyakov Yakov had the highest number of publications and article centrality. In this field, the literature published in the soil science journal Plant and Soil was the highest, but the literature with the highest citation frequency was published in the top journal Nature, and the research direction was mainly ecological and environmental science. In addition, according to the keyword co-occurrence analysis, the research content of plant belowground C input was mainly divided into two aspects: biology (plants and microorganisms) and environment (atmospheric nitrogen deposition, temperature rising and elevated atmospheric CO₂ concentration), and the influence of plant belowground C input on SOC contribution was systematically reviewed. Based on the above contents, this paper analyzed the future development trend of this field, and put forward several suggestions to the problems which existed in the current research, and provided a holistic idea for further study of the contribution of plant belowground C input to SOC.