Abstract: In this paper,the correlations between summer precipitation of Yangtze-Huaihe River Valley and spring temperature of upper atmosphere,such as 100 hPa,70 hPa,50 hPa and 30 hPa,are investigated. As well,the thermal structure anomaly features of upper atmosphere are analyzed during the preceding spring of the flood/drought in Yangtze-Husihe River Valley by using NCEP/NCAR data.Thus the strong signal key area of upper atmosphere thermal anomaly to flood/drought in Yangtze-Huaihe River Valley can be determined.The results show that the summer rainfall in Yangtze-Husihe River Valley possesses remote response,to a certain extent,to spring thermal anomaly of different upper atmosphere levels.Namely,the temperature anomaly feature of upper atmosphere can be regarded as a strong signal factor for the forecast of flood/drought in Yangtze-Huaihe River Valley.The thermal structure is anomalous not only in 2-dimensions but also in 3-dimensions before flood/ drought of Yangtze-Huaihe River Valley.The vertical sections of the spring and summer temperature anomaly before flood/drought of Yangtze-Huaihe River Valley describe reverse pattern for flood and drought years.Furthermore,the meridional wave train connecting the two hemispheres during flood/drought years in Yangtze-Husihe River Valley is revealed.This wave train feature may be related to some external forcing sources from underlying surface,for example,the sea-ice anomaly of the Antarctic region.This conclusion is further verified through the relevant diagnostic analysis on vertical E-F flux divergence.