Abstract: This study is based on the ten days’ soil relative moisture data of 196 observation stations in the Yangtze Basin from 1992 to 2012, using the Kriging interpolation method to explore the spatial and temporal distribution and seasonal variation characteristics of soil relative moisture contents in 0-50 cm soil layer depths in the Yangtze River Basin. Moreover, the reasons for soil relative moisture content changes were explored mainly from climatic factors and NDVI. The results showed that: 1) the soil relative moisture content in the Yangtze River Basin has been increasing since 1992, with a rate of interannual variation tendency of 026%/a. 2) the soil relative moisture content was higher in the southeast and southwest than in the northeast and northwest. 3) the increasing intensity of soil relative moisture content showed an order of spring < summer < winter < autumn. 4) The main reason for the increase of soil relative moisture content were decreased potential evaporation and increased NDVI in the Yangtze River Basin. Key words：soil relative moisture content; interannual variation; influencing factors; NDVI; the Yangtze Basin