Abstract:Four typical monitoring transects (C transect，E transect，G transect and H transect) along the lower reaches of Tarim river were selected．The results showed the following important points. (1) From the medium to extremely degraded regions, the relative density, relative cover and relative frequency of the annuals and perennials decrease gradually, while the relative density, relative cover and relative frequency of the shrub and arbor gradually increase, although the cover and the diversity of the vegetation tend to decline. (2) A total of fifteen species was found in the soil seed bank in the lower reaches of Tarim River, but the numbers of species decreased with increasing level of degradation. The seed bank density ranged from 250-2013 seed/m2, but the results showed marked differences in the seed bank density along the degradation gradients（F=7.922，P<0.05）.The decline rates varied among different degradation regions. (3) The vertical distribution of the seed bank was characterized by a decrease of the seed bank density with increased depth: 0-5cm occupied 71%, 6-10cm occupied 19%，11-30cm occupied 10%. In the medium degraded region, the life form of the seed bank was dominated by annuals, but the life form shifted from annual to perennials and shrubs with increasing level of degradation. (4) The Sorensen′s similarity coefficient between the seed bank and the standing vegetation was low, averaged 0.219. The number of co-occurring species both in the seed bank and the standing vegetation decreased with increasing level of degradation.