In order to explore whether the development of biological soil crusts (formed by cryptogamous plants, microorganisms and other related organisms cementing soil surface particles with secretions, mycelium and pseudoroots) could influence morphology and matter accumulation of Reaumuria soongorica (a salt-secreting xerophytic shrub) in arid desert area, the morphological characteristics and biomasses of plants in different age groups (seedlings, young plants and adult plants), separately growing in three types transect regions at the southern edge of Badain Jaran Desert covered by algae-lichen, lichen and lichen-moss, were investigated and studied. The results showed that:(1) with succession from the algae-lichen crusts to lichen-moss crusts, the morphological differences in current year plants of R. soongorica were no observed. However, the length of basal branches, projection area of transverse/longitudinal crown, and root length of plants older than five years were significantly reduced, respectively. At the same time, the number of basal branches of plants in 3-5 years growing in lichen-moss crusts obviously decreased compared with those growing in algae-lichen crusts, and the plants older than five years were dwarfed distinctly. (2) The development of biological soil crusts not only reduced the capacity of biomass accumulation in young or adult plants, but also diminished their root-shoot ratio. Moreover, the increase or decrease degrees of biomass accumulation in unit time were enlarged gradually with the prolonging of biological soil crust succession or increasing of plant age. (3) The indexes of morphology and biomass in R. soongorica plants had an extremely significantly positive correlation with the area percentage of physical crusts or algal crusts, while a very conspicuous negative correlation with that of moss crusts. Therefore, it is considered that the succession of biological soil crusts results in changing of area percentages of soil crusts, which causes the alteration of key ecological factors (such as soil moisture). As a result, the significant differences were induced in morphological characteristics and biomasses of R. soongorica plants possessing same plant age and growing in different types of soil crusts. Based on the above results, it suggests that the population construction of R. soongorica can be carried out by methods of planting seedlings and supplying seeds in the oasis desert transitional zone of arid sand area where soil crusts are developing from no crusts to lichen crusts stage, and of which the planting seedlings should mainly been taken in the succession of no crusts to algae-lichen crusts stage while the supplying seeds to lichen crusts stage.