Northern Tibet is the headstream region for the Yangtze, Nu (Salween River), Lancang (Mekong River), and their numerous tributaries and high mountain lakes. It is also a major livestock production centre in Tibet which is one of the nation′s five key livestock raising provinces. However, Northern Tibet is situated in an extremely harsh natural environment and hosts vulnerable ecosystems which are at risk from global climate change. Alpine grassland is not only the most important and largest ecosystem in this area, but also a key resource for supporting local people′s subsistence. In recent years, large areas of alpine grassland ecosystem of Northern Tibet have been severely degraded and threatened by soil erosion and desertification. Sustaining the environmental conditions of alpine grassland ecosystem in Northern Tibet is of vital importance for the Autonomous Region and the whole of China. Due to lack of comprehensive assessments, there is difficulty in identifying the spatial distribution of eco-environmental sensitivity and the priority regions of ecological and environmental construction in Northern Tibet. Therefore, major ecological problems and environmental sensitivities were analyzed and priority areas of ecological and environmental construction identified by assessing the spatial distribution of sensitivity to soil erosion, desertification and grassland degradation in Northern Tibet based on a comprehensive analysis of GIS data The results showed that: the areas sensitive to soil erosion accounted for 42.5% of the total land area and were mainly distributed in the eastern and central regions which comprise the economically relatively more developed and more densely populated areas of Northern Tibet, which seemed to indicate that soil erosion could deeply influence the economic development of Northern Tibet and also of Tibet as a whole. The areas sensitive to desertification, larger than those sensitive to soil erosion, occupied 78.8% of the total land area and were mainly distributed in the northwest of Northern Tibet. Their occurrence increased progressively from southeast to northwest. Degraded grassland accounted for 50.8% of the total grassland area. The degree of grassland degradation in the middle, eastern and northern regions of Northern Tibet was more serious, whereas the grassland degradation in the vast western region was relatively slight. The snow covered mountains and glaciers and the surrounding areas in Northern Tibet were more sensitive to changes is weather patterns, while the areas along the arterial traffic lines were more strongly impacted by human activities. The alpine grassland in these areas was rather severely degraded and susceptible to further degradation in the future. The areas most sensitive to soil erosion, desertification and grassland degradation are considered priority regions for future ecological and environmental construction in Northern Tibet.