This paper aims to explore the effect of restoration on alpine cold and sub-humid desertified land by revegetation, explain the response of plant community and soil microbial diversity to restoration, and provide scientific support for alpine desertification restoration. A study of restoration on desertified land was conducted and Elymus sibiricus was planted continually in the southeastern Tibetan. The diversity and community composition of vegetation and microbial organisms were monitored along with 3 years of revegetation. The results showed that Elymus sibiricus was constructive species and led to the restoring events. The number of plant species increased 13 and there were 14 new species invaded in community after 3 years revegetation, and the disappeared species was Ajania potaninii. The main types were ephemeral and plant species which need better water environment, revegetation increased plant biodiversity. Soil microbial community and microorganism changed greatly in seasons. The bacteria PLFA biomass were added with 1.2 folds (0-15 cm) and 1.8 folds (15-30 cm) at the two soil layers respestively, the fungi PLFA biomass were added 0.5 folds (0-15 cm) and 5.1 folds (15-30 cm) at the two soil layers respestively, and the actinomycetes PLFA biomass were added 1.5 folds (0-15 cm) and 4 folds (15-30 cm) at the two soil layers respestively compare to control at late of non-growing season (April) after 3 years revegetation, while microbial biodiversity increased significantly. Revegetation effective promoted restoration of plant community and soil microbial diversity on alpine cold and sub-humid desertified land, which would contribute to the restoration process of the alpine cold and sub-humid desert ecosystem.