Abstract: Land use research is crucial for understanding human-environment interactions and promoting regional sustainable development, and accurately characterizing land use changes serves as the foundation for optimizing territorial spatial patterns. To reveal the evolution of land use in karst mountainous counties, this study took Hezhang County in Guizhou Province as a case study. Based on six phases of land use data for the years 2000, 2005, 2010, 2015, 2020, and 2024, and employed methods including transfer matrix, dynamic degree, and comprehensive index of land use degree, the spatiotemporal characteristics and transfer processes of land use change over the 24-year period were quantitatively analyzed. The findings indicated that: (1) The overall pattern of land use change in Hezhang County was characterized by the expansion of cultivated land and the contraction of forest and grassland, with the evolutionary process comprising three stages, rapid development, structural adjustment, and restoration transition. (2) Two-way conversions between cultivated land and forest land accounted for more than 80% of the total conversions, and policy regulation was the core driving factor of land use change in karst mountainous areas. (3) Forest restoration during 2020-2024 had had positive effects, but there was a tendency to prioritize forest over grassland, which might undermine biodiversity and ecological functions. Future efforts should rely on the laws of land use change to formulate differentiated territorial spatial management strategies, thereby coordinating the relationship between county-level development and ecological conservation in karst mountainous regions.