According to the measured sediment data of the Yellow River in Qinghai in 1956-2012, the paper used adopted Mann-Kendall, Spearman, linear trend regression of testing method to analyze sediment change tendency.The results showed that in addition to that there was no obvious trend of increase and decrease of sediment in the upper reaches of the Yellow River in Maqu,Tangnaihai, the sediment concentration, sediment volume at other stations showed a significant decreasing trend.The sediment showed a significant decrease trend from 1980s to 2012. The mutation year points of sediment change in the Yellow River occurred mainly in 1987, 2000, 2005.That of Huangshui appeared in 1980 and 2002.The river sediment concentration, sediment discharge in mutation years decreases with leaping. The river sediment concentration and load is a minimum in 2000 and 2012.The analysis of reasons of sediment decrease showed that reservoir storage plays a dominant role in reducing the amount of sediment of Yellow River. The improvement of vegetation cover conditions because of implemented projection of soil and water conservation, grain-for-green, as well as increase of natural runoff plays an important role for the decrease of sediment in the basin.