Abstract:At present, the relationship between the spatial distribution characteristics of regional runoff and its influencing factors under the background of the Qinghai-Tibet Plateau is still unclear, and the value single station or the average value of multi stations of wet and dry index of is difficult to reflect the distribution characteristics of regional runoff. Using standard runoff indexes of different time scales, combined with empirical orthogonal function and singular value decomposition, the spatial distribution characteristics of wet and dry runoff in the upper reaches of the Yellow River from 1969 to 2012 and its relationship with three meteorological factors of precipitation, temperature and snow cover in the Qinghai-Tibet Plateau are analyzed. The results show that the wet and dry situation of runoff in the upper reaches of the Yellow River has a regional consistent main spatial distribution mode(mainly affected by meteorological factors)and a secondary spatial distribution mode of northeast-southwest inverse phase distribution(mainly affected by human activities). It is more likely that there will be high runoff or low runoff in summer and autumn than in winter and spring. Precipitation, temperature and snow cover on the Qinghai-Tibet Plateau are the main meteorological factors affecting the spatial distribution of runoff in the upper reaches of the Yellow River. Precipitation plays a major role in controlling the variation of runoff in the upper reaches of the Yellow River, and the seasonal effects of snow cover and temperature are more obvious. The northeast, east and north of the Qinghai-Tibet Plateau are the key areas affecting the wet and dry situation of runoff.