Estimation of carbon storage is one of the essential requirements for evaluating rangeland ecosystem services and economic evaluation of carbon storage in rangeland plans. Plant performance in carbon storage is a function of plant characteristics, environmental and management factors. Therefore, the relationship of annual carbon storage of Astragalus brachyanus with plant traits, habitat characteristics and range management in the mountainous rangelands of Rajan was investigated. The five sites in which the species were distributed and differed in physical characteristics were selected and coded based on the type of management (exclosure or exclosure; intensity of grazing, medium and low grazing) and geographical direction. At each site, vegetation was measured within 30 two-by-two-square-meter plots, located 10 m apart along six 50 m transects. At each location, 15 A. brachyanus plant stands with different dimensions were selected and measured while measuring their appearance characteristics, and their current year growth was cut to estimate carbon storage. Samples were transferred to the laboratory to estimate the carbon conversion factor. Two composite soil samples were also taken from each site. Topographic factors (slope, geographical direction and altitude) and management (grazing in study units) were also recorded at each location. In order to investigate the relationship between annual carbon biomass storage and environmental and management , partial least squares regression was used. Based on the results, carbon storage of A. brachyanus was significantly different. Annual carbon biomass carbon storage, with crown diameter, number of base and plant height, was directly correlated with type of management (grazing intensity).