By analysis of heavy rain,rainfall, hydrologic data and satellite cloud charts in the upper reaches of the Yangtze river in 1998, the basic characteristics of the heavy rain in the upper reaches of the Yangtze river in 1998 were summaried, and the direct impact of the heavy rain in the upper reaches of the Yangtze river, the activity of weather system over the plateau, the activity of cloud mass on the Yangtze river flood peak in 1998 was recognized.