The Ulmus Pumila open forest in Otintag Sandy Land is a intrazonal vegetation type distributed in the typical steppe belt. Compared to the around typical grassland area, the vegetation is denser, with a large number of trees, shrubs, and swamps. It has been a high quality winter pasture for pastoralists for thousands of years. In the last half century, the vegetation in the Otindag Sandy Land has been severely damaged due to over-exploitation and inappropriate grazing management. More and more sand dunes have been becoming bare, and the their livestock carrying capacity has becoming weaker. The ecological and economic value of Otindag Sandy land was seriously weakened. In recent years, with the national grass-animal balance policy and the grazing prohibition policy have gradually been implemented, the total amount of livestock has been reduced to some extent. However, large areas of the sandy land are still degrading. Considering the basic needs of herders, the total amount of livestock cannot be reduced without limit. In addition, moderate grazing is beneficial to health of the natural ecosystem. Therefore, how to improve the grazing management and how to make rational use of the pasture on the basis of maintaining good ecology are the problems necessary to explore. In this study, the typical natural vegetation of Ulmus Pumila open forest in Otintag Sandy Land was chosen as an example to investigate effects of different grazing utilization methods on vegetation and the suitable grazing utilization methods for sandy land were discussed. Two comparative plots were adjacent, with similar climate background, the geographical environment, and grazing intensity. However, due to different grazing utilization methods, the vegetation status was significantly different. The results showed that in the winter pastoral area, the Ulmus Pumila population reproduction, plant coverage, and number of plant species kept well, while in the summer pastoral area, the vegetation was seriously degraded and the sand dunes tended to flow. The most significant aspects of the vegetation degradation included (1) the natural reproduction of Ulmus Pumila was interrupted. Because of over destruction by livestock, the Ulmus Pumila seedlings died or failed to grow into the normal arbores; (2) a large number of shrub communities have degraded or disappeared; (3) herb coverage, plant species, the perennial herb proportion significantly reduced, and the proportion of annual and biennial herb increased; (4) the area of bare sand increased, and sand dunes tended to be activated. Therefore, we consider that sandy land is suitable for winter grazing and is not suitable for grazing in other seasons. The degradation of Ulmus Pumila open forest were not caused by climatic factor but by unreasonable grazing management. Referring to the traditional herding methods of pastoralists, we propose to implement seasonal inversion grazing in conjunction with the surrounding flat grassland areas, and use the sand land as a winter pastoral area.