【Objective】 Microbial communities contain a lot of rare species and play important roles in soil ecosystem functioning. However, the elevational patterns of rare microbes in soils and their effects by land-use types remain elusive for mountain ecosystems. 【Method】 In this study, soil samples were collected from farmland and forest along an elevational gradient ranging from 1 880 to 3 010 m in Laojun Mountain, Yunnan Province, China. The bacterial communities were analyzed based on high-throughput sequencing of the 16S rRNA gene. Rare species were defined based on their relative abundance and the rarity of bacterial communities was determined. The elevational patterns of rare bacterial communities and their underlying factors for the two land-use types were further explored. 【Result】 It was found that the bacterial rarity was 0.266±0.71 and 0.209±0.064 in the farmland and forest, respectively. The rarity in the farmland was significantly higher by 21.56% than in the forest and showed a significantly decreasing elevational trend. The main drivers of bacterial rarity were pH and electrical conductivity in both land-use types. The alpha diversity, such as the Chao1 index, Shannon index, and Evenness index of rare bacterial communities were significantly higher in farmland soil than in forest soil, with increases of 19.99%, 4.43%, and 0.64%, respectively. In addition, the Chao1 diversity index of rare bacteria of both land-use types, showed a significantly decreasing elevational pattern of 31.39% and 34.40%, respectively. Also, the Shannon index of rare bacteria of farmland soil showed a significant decrease of 4.93% with elevation. Compared to the forest, the rare bacterial communities in farmland had significantly higher alpha diversity and lower beta diversity, the latter of which indicates biotic homogenization. In addition, for forest soil, the relative abundance of Actinobacteria showed a significant U-shaped elevational pattern, and the relative abundance of Bacteroidota and Chloroflexi showed significant increasing and decreasing elevational patterns, respectively. However, there was no significant elevational pattern of all the dominant phyla in farmland soil. Overall, the community compositions of rare bacteria were significantly influenced by the land-use type, elevation changes, and their joint effects, where the land-use type showed the greatest effect. Rare bacterial communities in farmland and forest soils were mainly influenced by physicochemical properties such as pH, moisture, electrical conductivity, and total nitrogen, with pH having the strongest effect. Compared to farmland, the rare bacterial communities of forest showed significant relationships with more physicochemical properties and higher correlations, and thus had greater sensitivity to environmental changes. 【Conclusion】 In summary, the rare bacterial communities of both farmland and forest soils showed a significantly decreasing elevational distribution pattern in Laojun Mountain, which was mainly driven by environmental factors such as pH. The findings of this study reveal the important roles of land-use type and elevation on soil rare bacterial communities on mountainsides. These results will help to foster a deep understanding of the formation and maintenance mechanisms of soil rare bacterial communities under land-use changes and provide scientific guidance for the sustainable development of mountain ecosystem land resources.