Based on the measured monthly runoff and meteorological data in the upper reaches of the Bayin River basin during the period of 1959-2013,by using the methods of Mann-Kendall trend test,R/S analysis and the change rate of accumulation slope,monthly and annual variations of runoff,various trends and cycles were analyzed, the contribution rates of climate change and human activity on the run off were calculated. The results show that annual runoff had showed a significant increase trend from 1959 to 2013,with an increasing rate of 0. 2 * 10~8 m~3·(10a)~(-1) and a Hurst index of 0. 78,the period of wet /normal /dry year was about 20 years,the river had experienced its high water period since the beginning of 21st century; the major periods of decadal runoff variation was 21-22 years,and the primary period of annual runoff variation was 10-11 years. Asymmetrical distribution feature of runoff within the year had displayed so that the runoff from June to November had accounted for 64. 49% of the total,showing a single peak distribution,first increasing and then decreasing,the maximum monthly runoff had postponed since the beginning of the 21st century,with the annual distribution more concentrated; an abrupt change of runoff occurred in 2001; in the upstream of the Bayin River,climate change played dominant role,following by human activity,with the contribution ratio to runoff of 83. 06% and 16. 94%,respectively. This study could be useful for future water resource development and utilization and ecological environment protection in the Bayin River basin.