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Alxa desert steppe is one of severely the degraded rangelands in the Northwest China. Shrubs, as the dominant life form in the desert steppe, play an important role in protecting this region from further desertification. Chemical properties of three soil layers (0 to 10, 10 to 20 and 20 to 30 cm) at three locations (the clump center [A], in the periphery of shrub canopies [B], and the inter-shrub space [C], at least one m away from the edge of shrub canopies) were investigated in two prominent shrub communities (Zygophyllum xanthoxylum, Ammopiptanthus monglicus) in Alxa desert steppe. The results showed that: (1) soils in three layers at the clump center exhibited significantly higher contents of organic carbon (SOC), total N, total P, and lower pH value compared to the inter-shrub space. Soils in the 0 to 10-cm and 10 to 20-cm depths under periphery of shrub canopy showed significantly higher contents of SOC and total N, and slight, but significantly lower, pH value compared to the same soil layers in the inter-shrub space. However, there was no significant difference in total P in three soil layers between shrub periphery and inter-shrub space; (2) the soil enrichment ratios of SOC, total N, and total P at clump center were significantly higher, while ratio for pH significantly lower compared to the shrub periphery; and (3) SOC and total P contents at all locations around Z. xanthoxylum were higher, while total N and pH values lower compared to soils around A. monglicus. The enrichment ratios of SOC, total N, and total P at the same location were not significantly different between Z. xanthoxylum and A. monglicus. The litter-fall seems to influence the soil chemical properties at clump center, shrub periphery, and inter-shrub open space, resulting in "fertile island" under shrub canopies. This study shows that shrubs play a vital role in accumulating SOC and nutrients and maintaining soil fertility in Alxa desert steppe.