Over the past 50 years, the desert riparian vegetation in t he lower reaches of the Tarim River in western China degraded due to irrational management regimes . Little is known about the effect of vegetation degradation level on the structure and performance of soil seed bank in desertriparian vegetation. A field experiment was established to test this effect . The results showed that the density (892.6 seeds·m^{- 2} ) and species number (11 species) of soil seed banks in the moderate-desertification transects are relatively high.With the increase of desertification level the species abundance , density and biodiversity index of soil seed bank decrease . There is no significant effect of desertification intensity on the vertical density distribution of soil seed bank. However , over 70% of seeds were concentrated in the upper oil layer (0～2cm) . Plots at extreme desertification level showed a greater proportion of annual herbs compared to plots at heavy or moderate desertification levels , whereas perennial herbs and shrubs followed the inverse trend. These results indicate that the potential of the natural vegetation to restore naturally decreases with the increase of desertification level .