It is inevitable to use key species for projects of rangeland improvement and development. One of the successful projects for rangeland improvement and development is to use seeding with technical knowledge in order to have complex success in poor rangelands that are desert regions. The cultivation of environmentally adaption plants is one of the best biological methods to prevent desertification. The climatic and edaphic characteristics of the arid and desert regions create sensitive and fragile conditions for the growth and deployment of plant species. The aim of this study was to investigate the effect of Seidlitzia rosmarinus on vegetation and soil in in Shahroud – Chah bagher Region. In so doing, in 3 areas, 18 years old cultivar, 10 years old and Control area,  a  systematic random sampling was carried out along three transects. On each transect, 10 plots (10×10) meter at a distance of 50 meters from each other were placed. In total, 30 plots (10×10) were located in each area. In each plot, the characteristics of vegetation which included crown cover percentage, density, production and regeneration of Seidlitzia rosmarinus were harvested. In order to determine the soil characteristics, soil samples were collected from each depth of 0-30 cm and Soil characteristics such as: soil texture, pH, Organic matter and Ec were measured. The results showed that 5 species were introduced in 18 and 10 year-old cultivated areas. Four species of Zygophyllum fabago, Salsola rigida, Haloxylon aphyllum and Halothamnus subaphyllus were common in 18 and 10-year-old cultivated areas. Salsola arbuscula was observed in 10 year old cultivated area and Artemisia sieberi 18 year old cultivated area. Also, the cultivars of Seidlitzia rosmarinus showed that acidity, organic matter and clay and silt percentage increased compared to the control area. As for diversity indices Shannon Weiner and Simpson and Species richness indicators Margalof and Manning, no significant differences were found between Seidlitzia rosmarinus cultivars ages 10 years and 18 years old. The results of this research indicate that the plant is a key species to be used to cultivate and improve saline soils in the desertification of desert areas.