The distribution of sand dune in Qinghai Lake Basin is characterized by a surrounding lake specially concentration at EEN shore. Therefore, the wind sand can enter the lake from difference directions, in fact, max. quantity of sand comes fom east t west and north directions. According to the calculation by the formula, the wind drift sand discharge of eatering the lake is about 88.708×10⁵ t/a, the silt discharge of empting the lake by rivers about 3.577×10⁵ t/a, and the falling dust discharge from air about 3.036×10⁵ t/a, The sandy materials entering the lake were transported by the lake wave and currents from west to east, forming the subaqueous barriers. The sandy barriers gradually became higher and wider, and emerged from the water by which lagooas were insolated from the lake. At the same time9owing to strong evaporation9the lake began to shrink and its ecological envivonments to get deteriorated.