Abstract: Using the radiosonde data in summer of 1997 to 1998, the water vapor flux over the upper reaches of the Changjiang River from 925 hPa to 200 hPa are calculated. The relationship between the inflow of water vapor and the run-off over the area and contrast analysis between 1997 and 1998 is made based on the five-day and ten-day averages of net inflow water vapor. The statistical dependence is described and the relation between water vapor transportation and circulation situation is discussed.