Tree species selection is greatly critical to afforestation and vegetation restoration in arid and barren mountain areas. To examine the ecological adaptation strategies of different tree species to these special environments, and to supply scientific proof for tree species selection in stress environments, this study sampled whole root system of six tree species, namely Pinus thunbergii, Platycladus orientalis, which belong to conifer trees, Pistacia chinensis, Quercus acutissima, which belong to deciduous-arbor trees, Cotinus coggygria and Euonymus fortunei which belong to deciduous shrub and evergreen woody liana. The root architecture traits like horizontal and vertical distribution pattern were shown in coordination system to compare their difference, and fine roots morphological traits of 1 to 5 order roots were also examined through winrhizo root system. Finally, roots architecture and morphological traits of these tree species were compared to analyze the adaptive strategy of different tree species in this arid and barren environment. The results showed that there were significant differences among all tree species. The roots of three tree species, Pinus thunbergii, Platycladus orientalis, Euonymus fortunei, showed shallow rooted property, and their adaptive strategy to arid barren environment might depend on root exploration and water and nutrient utilization on soil horizontal direction. However, the other three trees, Cotinus coggygria, Pistacia chinensis, Quercus acutissima, showed deep rooted property, which indicated that these tree species would explore their roots to deeper soil for resources utilization. Secondly, the morphological traits of all tree species showed significant differences, and the fine roots of Euonymus fortunei were the most and the root length, surface area and root volume were the highest in all trees(P <0.05), which indicated that it had more abilities of rooting and water nutrient utilization. Thirdly, the root specific length of first and second order roots of Quercus acutissima and Euonymus fortunei were the highest in all tree species, which indicated that they had more ability to absorb water and nutrient. Finally, according to the root architecture and fine root morphological traits of every tree species, we conclude that trees are specific in root growth and root form, the distribution pattern of trees in soil could reflect the strategy utilizing limited resources, especially in arid and barren mountain areas. Thus, mixed forests model should be paid more attention and established during afforestation in these stress environments, e. g. conifer and broad leaved mixed model, arbor and shrub mixed model, to exert more and better ecological effects of forests in water and soil conservation.