As an important factor of surface processes,soil moisture has great influence on atmospheric circulation and weather climate of local and adjacent areas.Because the observation sites of soil moisture in the Tibetan Plateau(TP)are sparse and the observation time is short,we use a set of satellite retrieval data which has validated by field observations,to study the relationship between earlier soil moisture of TP and later precipitation of eastern China and its mechanism.The results indicate that with the global warming,the general soil moisture of TP has an obvious trend to increase.After removing the linear trend,we define the Tibetan Plateau soil moisture index(TPSMI)to characterize the interannual variation of TP soil moisture.Such variations of soil moisture have great conformance in 0~10cm,10~40cm and 40~100cm, which makes soil moisture interannual signal from spring continue into summer.The correlation coefficient between spring and summer TPSMI is 0.56.When the TPSMI is bigger,which means that the soil moisture of eastern TP is bigger,and when the soil moisture of western TP is smaller,there is a latent heat source(sensible heat source)in eastern(western)TP.The two heat sources together induce a cyclone-anticyclone-cyclone wave train from the west of TP through China mainland to northeast China,which presents a prominent quasi-barotropic structure through the middle and upper troposphere.This has great contribution to the enhancement of Northeast Cold Vortex,which leads to the outburst of cold air.At the same time,the South Asian anticyclone gets enhanced and eastward,while the Sub-tropical anticyclone gets enhanced and westward with the converge of warm moist airflow from south and cold dry airflow from north in the Yangtze River basin.In addition to the stronger rising movement,the summer precipitation of the Yangtze River basin is much more.On the contrary,when the TPSMI is smaller,the precipitation of the Yangtze River basin is much less.