We calculated monthly water vapor content using measurement data in 1976-2009 from Yining radiosonde station, and established W-e model suitable for the Ili River basin with ground vapor pressure, calculated the water vapor content in the Ili River basin in 1961-2009 combining with the DEM data, analyzed the temporal and spatial distribution characteristics of water vapor and precipitation with EOF and cross spectrum method, and researched water vapor transport characteristics during typical strong precipitation process in summer in dry and wet years. In the Ili River basin, the water vapor content at the west is more than at the east, the plain is more than the mountain, the windward slope is more than leeward slope, and downstream plain and upstream valley areas are high value areas with water vapor content of 13-15 mm. It is related to the terrain and distribution of the oasis towns. At 850 hPa and 700 hPa height, there is a maximum water vapor area, corresponding to an altitude around 2 000 m. Water vapor increased at inter-decadal scale and increased obviously in summer(0.48 mm/10a). Precipitation and water vapor EOF decomposition standardization fields show that their temporal and spatial distributions are extremely similar, and there are distribution types of climate vibration consistency and north-south opposite distribution type for the river valley. The fountainheads of water vapor give priority to Tropical Marine in rainy season, and water vapor content also is influenced by water vapor transmission from the Arctic Ocean.