[Objective] The spatiotemporal evolution and scale-dependent driving mechanisms of newly cultivated land（NCL） in western Jilin Province were analyzed, and cultivated land protection zones were delineated, in order to provide a scientific basis for spatially differentiated cultivated land reclamation and precise management. [Methods] Based on land use data from six periods between 2000 and 2024, methods including spatial autocorrelation analysis, geodetector, and self-organizing feature map（SOFM） clustering were used to systematically examine the multi-scale driving mechanisms of NCL and to delineate cultivated land development and protection zones. [Results] ① The total cultivated land area showed a pattern of “decrease followed by an increase”. NCL increased steadily after 2010, reaching 3.51×10⁶ hm² by 2023. Spatially, NCL was highly clustered（global Moran's I: 0.293—0.415）.② The driving factors exhibited significant scale effects. Reserve cultivated land availability was the dominant factor at the county level（q= 0.618）, while settlement accessibility and water resource conditions were more influential at the township and village levels. At the 5 km grid scale, landscape pattern factors became the core drivers.③ Significant interactive effects were identified between socioeconomic factors such as population density and cultivated land condition factors.④ Four distinct functional zones were delineated: ecologically constrained and vulnerable zones mainly in the east and northwest, where natural constraints strongly limited the potential of NCL; cultivated land priority protection zones in areas with convenient transportation and stable cultivated land use, where strengthened protection of basic cultivated land was required; cultivated land potential development zones with abundant reserve cultivated land resources suitable for reclamation and expansion; and NCL key control zones primarily in urban-rural fringes, where strict land development control and ecological protection policies were necessary. [Conclusion] NCL in western Jilin Province is concentrated in cultivated land-dense areas in the western and southwestern parts of the study area. The driving mechanisms exhibit pronounced scale effects, and the interactions between socioeconomic and cultivated land condition factors are significant. Therefore, differentiated management measures should be implemented to optimize the layout of NCL and coordinate food security with ecological protection.