Abstract: Abstract: Oil sunflower is a pioneer crop growing in saline-alkaline soil. However, its germination rate and seedling growth can be inhibited when soil salinity is extremely high and thus its yields can be decreased. In order to improve germination rate and survival rate of oil sunflower, increase its yields and outputs, a field experiment was conducted to investigate the effect of two planting hole sealing methods (sealed by soil and sealed by sand) on rhizosphere soil moisture and soil salinity in severe saline-alkaline soils of Hetao irrigation area, Inner Mongolia, China. Eight rhizosphere soil samples at depth of 0-40 cm were taken with 5 cm as a sampling layer from the plots of planting hole sealed by sand and planting hole sealed by soil at the sowing, germination and seedling stages of oil sunflower to determine the soil moisture and salinity. Meanwhile, soil moisture and soil salinity under the plastic film mulch and in open field between plastic film mulching were also detected. Germination rate, seedling survival rate, seedling growth, yields, and output from the plots of planting hole sealed by sand and planting hole sealed by soil were calculated. The results showed that the soil moisture at depth of 0-15 cm decreased but soil salinity increased from sowing stage to seedling stage, and significant or extremely significant differences were detected between different growth stages. In seedling germination and seedling stage, rhizosphere soil moisture at 0-10 cm depth in the treatment of planting hole sealed by sand decreased by 3.86% and 4.83% than that in the treatment of planting hole sealed by soil, decreased by 4.79% and 9.73% than that in the treatment of plastic film much, while the rhizosphere soil salinity at 0-15 cm depth in the treatment of planting hole sealed by sand decreased by 16.46% and 40.99% than that in the treatment of planting hole sealed by soil, decreased by 30.53% and 33.72% than that in the treatment of open field between plastic film mulch, and increased by 17.86% and 29.89% than that in the treatment of plastic film mulch. At the germination stage, the rhizosphere soil moisture at 0-10 cm depth in the treatment of planting hole sealed by soil was almost same as that in the treatment of plastic film much, increased by 3.44% than that of open field between plastic film mulch, and its rhizosphere soil salinity at 0-15 cm depth decreased by 16.84% than that of open field between plastic film mulch, increased by 41.07% than that of plastic film mulch. At the seedling stage, the rhizosphere soil moisture of planting hole sealed by soil at 0-10.0 cm depth decreased by 5.15% than that of field mulching with plastic film, increased by 4.42% than that of open field between plastic film mulching, and its rhizosphere soil salinity at 0- 15 cm depth increased by 12.32% and 120.11% than that of open field among and in plastic film mulching. The treatment of planting hole sealed by sand significantly shorted the germination days, improved germination rate and seedling survival rate, and promoted seedling growth of oil sunflower. The yields per plant in plots of planting hole sealed by sand were significantly lower than those of planting hole sealed by soil, but its yields per unit increased by 62.00% and output increased by 58.60%. This study indicated that planting hole sealed by sand significantly decreased rhizosphere soil salinity at seedling germination stage and seedling stage of oil sunflower, improved germination rate and survival rate, promoted seedling growth, and increased oil sunflower yields and output value per unit area. Planting hole sealed by sand should be an optimum method for sowing oil sunflower in severe saline-alkali land of Hetao irrigation area.