[Objective] This study aims to analyze the spatiotemporal evolution and scale-dependent driving mechanisms of Newly Cultivated Land (NCL) in western Jilin Province, and to delineate land protection zones, thereby providing a scientific basis for spatially differentiated reclamation and land use management.[Methods] The analysis was based on land use data from six periods between 2000 and 2024. Methodologies included spatial autocorrelation analysis, geographical detectors, and a self-organizing feature map (SOFM) network to systematically examine the multi-scale driving mechanisms of cropland expansion and to define land development and conservation zones.[Results] ① The total cropland area exhibited a pattern of initial decline followed by subsequent expansion. Newly cultivated cropland increased steadily after 2010, reaching 3.52 million hectares by 2023, with a strongly clustered spatial distribution (global Moran's I: 0.293–0.415). ② Analysis revealed significant scale effects in the driving factors. Reserve land availability was the dominant factor at the county level (q = 0.618), while settlement accessibility and water resources were more influential at township and village levels. At a 5 km grid scale, landscape pattern factors became the primary drivers. ③ Significant interactive effects were identified between socioeconomic factors, such as population density, and land-use conditions. ④ Four distinct functional zones were delineated: Ecologically vulnerable zones in the east and northwest, where natural constraints limit reclamation potential; Priority protection zones in stable agricultural areas with convenient transportation, requiring enhanced prime farmland conservation; Potential development zones with abundant reserve land resources suitable for expansion; and Key control zones in urban-rural fringes, where strict land development controls and ecological protection policies are needed.[Conclusion] NCL in western Jilin is concentrated in cultivated land-dense areas in the west and southwest. The driving mechanisms exhibit clear scale effects, and interactions between socioeconomic and land use factors are notable. Therefore, differentiated management measures should be implemented to optimize the layout of Newly Cultivated Land and balance food security with ecological protection.