Populus euphratica (P. euphratica), at Tarim Nature Reserve, growing in their natural habitat represents a valuable resource for elucidating mechanism of acclimation to environmental constraints. P. euphratica is a salt-tolerant tree species growing in saline semi-arid areas. It is one of the stress-tolerance and desert-grown species. Therefore, the P. euphratica has been treated as main protecting object and the Tarim Nature Reserve is one of two P. euphratica Reserves in China. The nature reserve is located in the middle reach of the Tarim River, Xinjiang. It is not only the world's largest intact and unfrequented area of Populus euphratica forests, but also plays great significant role in maintaining the ecological balance of the Tarim Basin. However, the Populus euphratica Nature Reserve's eco-environment is getting more and more degenerated due to the human activities in recent years. This paper analyzed the ecological frangible factors and their influence mechanisms on the nature reserve eco-system stability using 3S technologies. The results showed the eco-environmental condition of P. euphratica is fragile and the ability of insisting on the artificial influence is weak because of the harsh climate, topographical conditions, and human irrational water use and land resources. The shortage and exhaustion of surface water, as well as descending of groundwater depth, make Populus euphratica forests deteriorating. The protecting strategies are suggested in this paper according to the research analyses.