Abstract: Soil salinization is a common stress on shelterbelts in arid regions around the world, which affects the cycling and maintenance of soil nutrients mediated by bacteria and threatens the stability of desert shelterbelt ecosystems. Bacterial communities consist of both common and rare species, but their roles in salinity stress responses remain unclear. The purpose of this study was to determine how rare and common bacteria respond to salinization, as well as the effects on soil function. Thus, soil bacterial community and carbon, nitrogen, and phosphorus-related enzyme activities along the salinity gradient in the Tarim Desert Highway shelterbelt formed by long-term saline irrigation were investigated. The rare and common bacteria were identified using the 0.01% relative abundance threshold method, and the soil function was characterized using the multifunctionality and vector methods. The results showed that: (1) The species richness of rare bacteria in the shelterbelts decreased significantly with soil salinity (P<0.05). Soil salinization significantly altered the community composition of rare bacteria (ρ=0.293, P<0.01) and common bacteria (ρ=0.205, P<0.01), with rare bacteria exhibiting greater variation. (2) Soil bacteria in the shelterbelts were limited by phosphorus but not nitrogen (vector angle >45°). As soil salinity increased, soil phosphorus/nitrogen cycling function (r=−0.190, P<0.05) and enzyme multifunctionality (r=0.253, P<0.01) decreased and increased, respectively. (3) The common bacteria were positively correlated with soil carbon cycle function (vector length) for species richness (r=0.173, P<0.05) and community composition (r=0.181, P<0.05), as well as soil enzyme multifunctionality (partial r=0.177, P<0.01) for community composition. The findings imply that the rare taxa, rather than common taxa, dominated the responses of the bacterial community in shelterbelts to salinization, and that the mechanisms of these two groups in shaping the soil function were different, with common bacteria acting as the primary driving force.