To elucidate the spatial distribution patterns and environmental drivers of soil bacterial communities in Larix gmelinii var. principis-rupprechtii plantations across different latitudinal gradients, eight representative plantation sites spanning the species' main distribution range were selected. Soil bacterial community composition was characterized using high-throughput sequencing technology. The patterns of community structure and diversity along the latitudinal gradient were analyzed via one-way ANOVA, Pearson correlation analysis, and redundancy analysis (RDA) so as to provide a scientific basis for rational management of forest ecosystems and soil quality. The results showed that: (1) Proteobacteria, Acidobacteriota, and Actinobacteriota were the dominant bacterial phyla. At the genus level, Candidatus_Udaeobacter and RB41 were widely distributed dominant taxa, whereas Delftia was identified as a site-specific dominant genus in the Taibai plot. (2) The relative abundances of Proteobacteria and Methylomirabilota significantly decreased with increasing latitude, whereas Actinobacteriota and Verrucomicrobiota showed significant increasing trends (P<0.05). Alpha diversity of soil bacteria did not vary significantly along the latitudinal gradient (P>0.05), whereas Beta diversity differed significantly among latitudinal zones (P<0.01), showing an overall fluctuating pattern characterized by an initial increase, followed by a decrease, a subsequent increase, and a slight decline. (3) Microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents did not show significant variation along the latitudinal gradient. (4) Soil bacterial community structure was significantly influenced by soil bulk density, soil mass moisture content, mean annual precipitation, MBC, MBN, soil readily available potassium, and canopy closure (P<0.05). Alpha diversity indices were primarily affected by canopy closure, elevation, MBC, and cation exchange capacity (CEC) (P<0.05). The relative abundances of major bacterial phyla exhibited distinct trends across the latitudinal gradient, whereas Alpha diversity, MBC, and MBN showed no significant latitudinal patterns. Overall, soil bulk density, soil mass moisture content, mean annual precipitation, MBC, MBN, clay content, CEC, elevation, slope, and canopy closure were identified as key environmental factors shaping the spatial distribution of bacterial communities, and serve as important drivers of their variation along the latitudinal gradient. These findings provide a theoretical support for a deeper understanding of the responses of soil bacterial community structure and diversity to latitudinal changes in L. gmelinii var. principis-rupprechtii plantations.