The impacts of climate change and human activities on the runoff in the upper reaches of the Jinghe River Basin were investigated using the climate elasticity method based on the hydrological and meteorological data from 1973to 2012.The results showed that the annual runoff decreased significantly with a rate of-13.1mm/10aand an abrupt change occurred around year 1985.The climate change accounted for 36.8%~43.8%to the decreasing in runoff,while human activities accounted for 56.2%~63.2%.Both of the climate change and human activities can result in the decline of runoff in the upper reaches of the Jinghe River Basin,but human activities played a dominant role.