This research was supported by The Gansu province meteorological bureau and university cooperation project"Numerical Si mulation of the Influences of Tibetan Plateau Vegetation Variability on Regional Cli mate";The science andtechnology bureau of Sichuan province applicationtechnology research and development project"Study of Ecological SystemEvolutionin Sichuan andits Mechanism"(07JY029-036);The opening project of the Cheng-duinstitute of plateau meteorology China meteorological administration"Study of Influence of Tibetan Plateau Vegetation Variability on Regional Cli mate and its Mechanism"(LPM2006020).