[Objectives] The relation between community coverage of Leymus chinensis and yields of runoff and sediment were explored to provide references for the control of soil and water loss in those grassland which is dominated by Leymus chinensis. [Methods] Experiments using artificial rainfall and wind tunnel were conducted to study the yield of runoff and sediment and the resistance to wind erosion of five cover scales of Leymus chinensis grassland. [Results] At certain slope degree, the runoff-yielding time was delayed when the cover scale gradually increased. The accumulated decreasing rate of runoff yield loss was less than the corresponding one of sediment yield loss. When Leymus chinensis community coverage increased from 20% to 100%, the wind erosion amount decreased by 96.78%; When Leymus chinensis community coverage increased from 60% to 80%, the relative decreasing amount of wind erosion loss was the largest in comparison with the ones of other adjacent communities. The wind erosion amount collected by the sand sampler in 0~23 cm height account for more than 70% of the total amount of wind erosion. [Conclusion] The runoff and sediment yields of Leymus chinensis land were correlated closely with cover. I.e., with the increase of cover, the accumulated runoff and sediment yield showed a trend of declining. It showed a negative correlation between the amount of wind erosion and Leymus chinensis cover scale and a positive correlation between the amount of wind erosion and wind speed.