The relationship between the precipitation of the mid-lower reaches of the Yangtze River(MRYR)in summer with the soil temperature of the Tibetan Plateau(TP)in previous winter and spring is investigated. Data analyses show that the soil temperature abnormality affects the drought and flood in MRYR on seasonal scale,and there is obvious correlation between the soil temperature of TP and the precipitation in MRYR. The soil temperature anomaly of TP in the previous winter and spring is positive on the south of TP and negative on the mid-north in flood years, in contrast,the anomaly is positive in the mid-north and negative in the south in drought years. The distinct anomaly of soil temperature lies the layer between 40cm and 1.6m under the ground surface. Both data analyses and model simulations suggest that the general circulation in the north hemisphere may produce teleconnection and form the low frequency wave propagation on seasonal scale in response to the thermal abnormality of TP,thus,affecting the subsequent summer precipitation in MRYR. These processes may imply that the teleconnection dynamical mechanism is one reason for formation of regional drought and flood.