[Background] Climate change and human activity are the major influence factors on streamflow. The effects of climate change and catchment changes on the long-term water balance are of considerable interest at a range of spatial scales. Haihe basin is the most serious and prominent area in China,studying the effects of climate and human activity on streamflow is of great significance for water resources management. [Methods]The Budyko framework has been widely used to attribute changes in streamflow to the effects of climate and human activity. And the method of double mass curve (DMC) is often used in the analysis of the consistency of hydro-meteorological factors and their inter-annual variations because a plot of the two cumulative quantities during the same period exhibits a straight line. In this study,we chose the mountainous area of Haihe basin as our study area,and used Budyko hypothesis and double mass curve to analyze the effects of climate and human activity on streamflow. [Results]The results show that: 1) the precipitation,streamflow and potential evapotranspiration in Haihe basin are all obvious decreased trends,while the temperature is an obvious increased trend; the mann-kendall analysis results show that the streamflow has an abrupt change in 1980; 2) the study period (1957-2000) can be divided into a reference period (1957-1979) and a change period (1980-2000) based on the change point of 1980,the mean streamflow in the reference period and the change period are 115.12 mm and 69.94 mm,respectively,and experiences a large reduction of 45.18 mm; 3) in this change,the effect of climate change were 10.89 mm and accounted for 24.11%,and among them,the effect of precipitation change was decreasing 13.94 mm (accounted for 82.05%) and the effect of potential evapotranspiration was increasing 3.05 mm (accounted for 17.95%); 4) After 1979, human activities began to have a significant effect on watershed streamflow; among the change of streamflow in Haihe basin,the effect of human activities were 33.87 mm and accounted for 74.97%. [Conclutions]There are many factors affecting the runoff of the river basin,such as land use change, water conservancy project,water resources development and so on; human activities affect the process of regional water circulation by changing the type of underlying surface,and Haihe Basin is one of the most serious areas affected by human activities. Most studies showed that the effect of human activities on streamflow is far greater than the effect of climate change,and in this study,the results also show that for the changes of streamflow in Haihe mountainous area in 1957-2000,the major factor is human activity and its contribution rate is large as 74.97%,while the contribution rate of climate change is only 24.11%.