Abstract: Grassland desertification is one of the most serious ecological and environmental problems in our country. To investigate changes in soil nitrogen under different vegetation restoration measures in desertified grasslands, the soil nitrogen content under 4 vegetation restoration measures in a semi-humid alpine region in northwest Sichuan were measured to elucidate the characteristics of soil total nitrogen and components in 0-60 cm soil layer during ecological restoration. After three years’ restoration; fencing with mixed sowing of oat and grasses, fencing with sowing of grasses and natural recovery after fencing, all restoration procedures increased vegetation cover and improved soil physical properties, particularly fencing and sowing oat and grasses. Increasing soil N content appeared as microbial biomass N>N{Invalid MML}-N>N{Invalid MML}-N>available N>total N. Compared with the severely desertified grassland, vegetation cover after fencing and sowing with oat and grasses increased to 74.1%, soil bulk density decreased to 1.39 g/cm³, while surface temperature at noon in summer decreased from 41.5 ℃ to 23.0 ℃. The total N content, available N, N{Invalid MML}-N, N{Invalid MML}-N and microbial biomass N in oat quadrats increased by 255.8%, 270.3%, 299.5%, 357.8% and 745.9% respectively. Soil particle composition and bulk density were significantly correlated with soil total nitrogen and N components in desertified grassland. We concluded that sowing oat with grass is an effective strategy for repairing desertified grasslands. Oats play the role of a pioneer species because of its drought resistance, tolerance of low fertility and strong tillering, promoting the growth of grass.