Water cycle is one of the most active processes in the interaction among ocean,land and atmosphere,and affected significantly by climate change.This paper evaluates the changes of water cycle components including precipitation,evapotranspiration,surface runoff and water vapor in China and ten river basins since 1979 based on ground based observations and reanalyses.Results show that the atmospheric water vapor and water vapor budget have shown significant increase trends during 1979-2018 in China.But,a weak downward trend of atmospheric water vapor was found at the Songhua River Basin and the Southwest River Basin spatially.Except for the Northwest River Basin,where annual precipitation increased significantly,changes of precipitation in other river basins were not significant.Areal averaged annual actual evapotranspiration increased slightly in China,but decreased obviously at the most River basins in South China.As for surface runoff,a clear increase trend was detected at the Northwest River Basin,but negative trends were found at the majority of River basins in North China,while trends were complex at the River basins in South China.Relative to 1979-2000,annual mean temperature in China increased by about 0.63℃,and annual precipitation and atmospheric water vapor increased about 0.5% and 1.2%,respectively,in 2000-2018.Meanwhile,both inflow and outflow of water vapor decreased,and precipitation recycling ratio increased by 10.9%.Spatially,the internal water recirculation was more active than before in 2000-2018 at the most river basins escept for the Songhua and Liaohe River basins in Northeast China.Precipitation produced by local evapotranspiration and inflow water vapor were both increased at the Haihe,Yellow,Huaihe and Northwest River Basins.At the Songhua,Liaohe,Yangtze,Pearl and Southwest River Basins,increase of precipitation from local evapotranspiration was offset by more significant declining of precipitation from infow water vapor,and this effect was more obvious at the Liaohe River Basin than others.Precipitation produced by local evapotranspiration has increased slightly,but overall change of precipitation was not significant at the Southeast River Basin.