Abstract: Abstract：In this study, an extended hydrological sensitivity method was proposed to quantify the impacts of climate change and human activities on seasonal river runoff. The second-order mixed partial derivate, which was obtained based on the Taylor's expansion of runoff change, was taken to be the magnitude of the interaction impact between climate change and human activities. We applied the equation to separate the extent of the impact of climate change, human activities and their interactions on dry season runoff. Moreover, an ABCD model including snowmelt module was used to calculate the change of the soil water storage and the groundwater storage. By taking the Lhasa River Basin as a case study, it was found that the runoff in the dry season exhibited a less significant upward in the last 60 years. Climate change, which causes an increase in the dry season runoff, is the dominant factor leading to the increase of runoff, followed by human activities and their interaction effects which cause varying degrees of decreases.