To clarify the effects of environmental conditions on the forest structure of P. euphratica forest, replicate censuses were carried out on the P. euphratica forest in Ejina oasis. The maximum height of 14m of P. euphratica forest was estimated. The frequency distributions of living tree height (H_L) in 2005, 2009, 2010 and 2011 are bimodal, indicating the continuous regeneration under sparse canopy. Moreover, the increase in density of small trees including seedlings and root sprouts showed an active response of P. euphratica to the changes in environmental conditions for 6 last years. As the root sprout is one of the main way of regeneration of P. euphratica, distinction of small trees between seedlings and root sprout is the next important theme. P. euphratica showed a significant (Ia=1.942, P=0.0002 for survivor; Ia=1.507, P=0.0064 for new) contagious distribution forming remarkable clumps and other plants (Sophora alopecuroides　etc.) growing on the forest floor showed almost the same spatial patterns. P. euphratica showed a positive association with EC which showed significant (Ia=2.025, P=0.002) aggregation. Therefore the soil condition with a little high salt content may have a great effect on the establishment and survivor of these trees preferring to grow in arid condition.