Abstract: Using a five-layer primitive equations model,Typhoon 9106 in the South China Sea is investigated in terms of its thermodynamic effect on the 1991 Meiyu process over the area of so-called Yangtze-Huaihe-River Basin. Numerical experiments show that the typhoon contributes much to the earlier-than-usual ending of the Meiyu in 1991, mainly through physical mechanisms of (1) horizontal tropospheric flow fields excited by heation source of typhoon disturbance, which weakens Southwest Monsoon transporting moisture to the basin, resulting in less convergence of moisture flux; (2) meridional vertical circulation cell affecting summer monsoon in East Asia,which inhibites monsoon circulation during the Meiyu period; and (3) the subtropical high in West Pacific, which is pushed northward by the storm to end the Meiyu.