Abstract: Based on the ground meteorological observation data of sunshine hours,average total cloud cover,precipitation days and relative humidity from seven meteorological stations in the source area of the Yellow River from 1961 to 2017,the variation trend and influencing factors of sunshine hours in the source area of the Yellow River in recent 57 years were analyzed. It was found that the spatial distribution of annual sunshine hours in the source area of the Yellow River was more in the north and less in the south. Maduo and Xinghai in the north had the most sunshine hours,while Jiuzhi and Hongyuan in the South had the least sunshine hours. The spatial distribution of seasonal sunshine hours was similar to the annual average sunshine hours. The interannual variation of sunshine hours in the source area of the Yellow River indicated that the annual sunshine hours in Xinghai and Hongyuan showed a downward trend,with a downward trend of-28.6 h/10 a and-18.4 h/10 a respectively,and the rest showed an upward trend,with Maduo showing the most obvious upward trend,and the ratio was 22.4 h/10 a. The monthly variation of sunshine hours in the source area of the Yellow River showed obvious characteristics of three peaks and two valleys. There were three high value periods in April,August and November,and two low value periods in June and September,of which the sunshine hours in September were the lowest in the whole year. The results of periodic analysis showed that the periodic changes of sunshine hours in the source area of the Yellow River were mainly 2 a,4-6 a,10-13 a and 22-30 a. Sunshine hours were significantly negatively correlated with the total cloud amount,precipitation days and relative humidity. In spatial distribution,sunshine hours increased significantly with the decrease of total cloud amount,precipitation days and relative humidity from south to north. The correlation between sunshine hours and total cloud cover was the best,especially the change of seasonal total cloud cover was the most sensitive to the change of annual sunshine hours. The spatial distribution of total cloud cover and sunshine hours was just opposite. The decrease of precipitation days and relative humidity was one of the important reasons for the increase of sunshine hours. The source area of the Yellow River is rich in solar energy resources,and the range from the source of the Yellow River to Jimai showed a continuous increasing trend,which is conducive to the development and utilization of solar energy resources.