Abstract: Study is undertaken of Tibetan sensible heat flux features in spring prior to the summer flood/drought in the milled and lower reaches of the Yangtze River (hereafter referred as MLRY). Analysis of the difference of atmospheric temperatures and 0 cm soil temperatures indicates that the Tibetan thermodynamic structure displays noticeable discrepancy preceding flood/drought in MLRY: there exists an air-ground temperature difference pattern of "high in South and low in North" in spring before flood and "high in North and low in South" before the drought. Sensible heat fluxes on Tibetan Plateau show that the spring flux difference (of flood and drought in MLRY) in the target regions takes on "high in South and low in North" manner. Outcome of simulations suggests that Tibetan plateau sensible heat fluxes in spring on a south-north inhomogeneous basis lead to the summer precipitation abnormity in MLRY, that is, the Tibetan sensible heat flux anomaly is one of the "strong signals" which contribute to the flood/drought in MLRY.