The investigation of soil respiration dynamics under different land uses is critical for understanding the ecosystem carbon cycle from an agro-pastoral ecotone of northern China. In this study, three typical land uses, including Free-grazed grassland(FG), Ungrazed grassland(UG), and Oat cropland(AN), were selected in an agro-pastoral ecotone of Guyuan, Hebei. Soil respiration, top soil temperature, and water content were determined by using LI-8100A(Li-COR, Lincoln, NE)during the growing season(from June to September). The results indicated that the dynamics of soil respiration were consistent under three typical land uses, showing soil respiration rates were higher in July and August than in June and September. During the growing season, the average rates of soil respiration in FG, UG, and AN sites were 3.41, 4.06, and 3.58 mumol·m~(-2)·s~(-1), respectively. The diurnal variation in soil respiration exhibited unimodal patterns in FG, UG, and AN sites. Negative values were observed for AN in the morning during September 30. The cumulative soil respiration in UG(766 g·m~(-2)) was higher compared to that of AN(661 g·m~(-2))and FG(644 g·m~(-2)). Soil temperature was the key factor controlling the dynamics of soil respiration. The Q10 value(temperature-dependence of soil respiration)in AN was higher than that in FG and UG, which indicated that the conversion of grassland to cropland in this region could increase the loss of organic carbon in the background of global warming.