Abstract: In the seriously desertified grassland, the sand dunes which have set high-parallel reed sand-barriers for 2-3 years and 4-5 years were selected as research objects. The vegetation and the soil seed bank in the different places of the dune (windward side, leeward side, lowland of sand dune) and the sand-barrier(windward side, leeward side of the barrier, land between two barriers) were investigated. With the dunes without barriers as control, the authors studied the functions of the high-parallel sand-barrier.Resultsshow that high-parallel sand-barrier can increase the plant's coverage and species diversity, increase the quantity and sort of seeds in the soil, and accelerate the development of biological crusts.