Abstract: By analyzing the meteorological data and soil moisture data from 1990 to 2017 in temperate meadow steppe in Ewenki Autonomous Banner locating in northeastern Inner Mongolia,the correlation between the soil moisture dynamics and climatic factors was investigated.The results showed that the average temperature was increased at a rate of 0.47 ℃/10 a from April to October during 1990 to 2017 in the study area,while the precipitation was decreased at a rate of 28.3 mm/10 a;the correlation between soil moisture in different layers and sunshine hours,temperature and relative humidity was minor;there was a very significant positive correlation between soil moisture and precipitation(P<0.01);the soil moisture in layers of 0-10,10-20,20-30,30-40,0-50 cm was very significantly negatively correlated with evapotranspiration(P<0.01),and that in layer of 40-50 cm was significantly negatively correlated with evapotranspiration(P<0.05).According to correlation analysis,evapotranspiration and precipitation(from April to October)were selected as the main factors affecting soil weight and moisture,and the regression equation was established.