Moisture transfer associated with the sustained heavy rain in 1991 over the Jianghuai valleyis analyzed,It is shown that 2/3 of the moisture that entered to the Jianghuai Valley during July1—10 1991 came from the Bay of Bangal and the remaining 1/3 from the South China Sea.The evolution of moisture transfer during May 1 to July 10 1991 shows that both the mois-ture transfer from the Bay of Bangal and from the South China Sea are enhanced simultanouslyand they are corresponding to the heavy rain over the Jianghuai Valley.