In this paper,the NCEP/NCAR reanalysis data and the disturbance flux field of water vapor transport (the integration of whole atmospheric column above the ground minus its mean field) are used to analyze the seasonal variation of water vapor transport over the Changjiang and Huaihe River Valleys for the 1957-2001 period. Differences of moisture transfer during the Meiyu period between the droughts and floods years are also investigated. Results show that there are great differences between the mean vapor transfer field and the disturbance one. The mean water vapor transport from the Bay of Bengal greatly influences the precipitation in the eastern China,while the disturbance one from the same source exerts primary impacts on the district of the northern Indian. The disturbance moisture transport which affects the Changjiang and Huaihe Valleys is mainly from the South China Sea. The key factor responsible for positive precipitation anomaly over Changjiang and Huaihe Valleys is the intense moisture transport from both the western Pacific Ocean and the northern China .It is also revealed that disturbance water vapor transport weakens the mean one,because the disturbance transport direction is opposite to the climatologic mean and the divergence of disturbance field manifesting is out of phase compared with the mean one during the anomalous Meiyu rainfall period over Changjiang and Huaihe Valleys.