As a result of combined impact of global climate change and anthropogenic disturbance,global wind speed has been found to decrease to different extent. The decrease of the wind speed increases the surface boundary layer thickness,reduces the heat and moisture exchange rate,changes the near-surface micro climate,and reduces the wind erosion,which affects plant growth and other ecosystem processes. The climate characteristic is strong wind,little rainfall,high evaporation and strong solar radiation in Inner Mongolia grassland. Because of the unreasonable land utilization way such as overgrazing and farming all throughout the year,Inner Mongolia grassland ecosystem has strong sensitivity of natural and human disturbance. In this study,we simulated reduced wind speed with wind deflector installed in semi-arid grassland,simulated grassland utilization intensity variation through different mowing intensity,and monitored variation of near surface soil moisture input and output and community regeneration. The result showed that the wind deflector could reduce wind speed effectively; the reduced wind speed could contribute to restrain the soil moisture evaporation loss,improve the regeneration capacity after the mowing conduction; so wind speed reduction manifested positive effect on semi-arid grassland ecosystem in Inner Mongolia. Combined with mowing conduction,wind speed reduction could relieve the drought stress of mowing on grassland ecosystem to certain extent,but wind speed reduction could not change the impact of mowing conduction.