Abstract: The characteristics and difference of the water vapor transport in the East Asian,South Asian and Indian monsoon region in1997—1999 summer are analysed by using the monthly data of water vapor and wind fields at 1000—300 hPa levels analysed by ECMWF.The analysed results show that:① the positive meridional flux of the water vapor transport in the Indonesia–south Japan-south China from weak to strong then to weak from 1997 summer to 1999 summer,but in the Indonesia-north Australia from strong to weak then to strong;②the positive zonal flux of the water vapor transport,in1997 summer the area of the east-west is wider than1998 summer's and 1999 summer's,but the area of the south-north is narrower;③the negative advection of water vapor in the area of south-east China,south sea and the vicinal sea of Japan in1998 summer is biggest;④ the divergence of wind in Arabian Sea and Bengal Bay in1998 summer is weakest,in East Asian and west pacific the change is very large in these three year's summer.