Based on meteorological and hydrological observation datasets in the upper reaches of the Bailong River during 1961-2010,the linear tendency,fluctuation,periodicity and persistency of temperature,precipitation and runoff,as well as their relationships were analyzed using Mann-Kendall test,R/S analysis,Morlet wavelet analysis and multiple linear regression method. The results show that the temperature and runoff had significantly increasing and decreasing trend,at the rate of 0. 38℃ /10a and-3. 94 * 10~8m~3 /10a,the precipitation appeared weakly decreasing trend,at the rate of-3. 00mm/10a. The temperature and precipitation would have upward trend,while the runoff would decrease in the near future. A consistent master cycle and sub-period of temperature, precipitation and runoff were easily detected. There was an obvious positive correlation between runoff and precipitation,while the correlation between runoff and temperature was negative. Climate change and human activities both had significant impacts on the runoff change. The result of multiple linear regression shows that variations of runoff mainly attributed to human activities before 1990. Climate change and human activities both became the main factors influencing the runoff change after 1990.