Grasslands, as a critical terrestrial ecosystem, play a significant role in mitigating global climate change through their carbon storage and sink functions. Despite growing interest, a systematic overview of the research landscape is lacking. This study employs bibliometric analysis to map the global research on grassland carbon sinks from 2000 to 2024, based on 776 articles from the Web of Science (WOS) Core Collection. We analyze publication trends, collaboration networks (countries, institutions, authors), and thematic evolution using VOSviewer and CiteSpace. Results show a rapid increase in publications, particularly after 2017, with China and the USA being the most productive countries. The Chinese Academy of Sciences is the leading institution. Keyword analysis reveals four major research clusters: (1) grassland carbon sink dynamics and mechanisms, (2) CO2 exchange and flux measurement, (3) climate change impacts and net primary productivity, and (4) carbon budgets and balance. Emerging frontiers include "carbon neutrality," "drought," and "degradation." This analysis provides a comprehensive overview of the current status, research hotspots, and future trends in the field, offering a valuable reference for researchers and policymakers to advance grassland management and address climate change.