Nowadays green house gases such as carbon have the most effect on global climate changes that can be decreased by plant and soil carbon sequestration of rangelands. Livestock grazing has high potential to decrease or increase carbon storage. So this research investigated the effects of enclosure on plant carbon storage in rangeland of enclosure (Shah Tappeh-Chah Mahmood) and no enclosure (Chiro) with dominant spices of Artemisia aucheri in Semnan province. Plant sampling was done in key areas by random-systematic method with 4 transects of 100m and 40 plots of 1‎×1m2. Then plant and soil parameters evaluated in each plot and carbon determined by Ash method. The data analyzed by SPSS v.16 software. The result showed that there is a significant difference between plant cover, gravel, bare soil percentages and also aerial and underground biomass and litter of Artemisia aucheri in two regions. The total biomass in enclosure rangeland with 11467/3 kg/ha was more than no enclosure rangeland. Root coefficient alteration (enclosure: 12/67% and no enclosure: 12/3%) was more than the other organs and there was no significant differences between coefficient alteration of organs and litter of Artemisia aucheri in two regions. The result also showed that there is a significant differences between carbon sequestration of Artemisia aucheri organs (level: 1%) and litter (level: 5%) in two study areas. Regarding to the effect of enclosure on plant cover and carbon sequestration increasing, it's suggested to protect plant cover in grazing management programs.