Abstract: [Objective and Method]Taking the degraded Seriphidium transiliense desert grassland in northern Xinjiang as an example, the soil microorganisms and enzyme activities of the different degraded series (moderate degradation grassland, severe degradation grassland and extreme degradation grassland) are analyzed. [Result]The results showed that the number of bacteria was the largest, which was dominate, and followed by actinomycete and fungi in the degraded grassland. At 10-20 cm soil layer, the differences of the number of bacteria, actinomycete and the total number of microorganisms were notable among the degraded grassland, and the difference of the number of fungi was shown only between severe degraded grassland and extreme degradation grassland. Compared with the moderate degradation grassland and severe degradation grassland, the activities of soil alkaline phosphatase, dehydrogenase and invertase were notablely increased at 0-10 cm soil layer in extreme degraded grassland. Catalase Activity in severe degradation grassland was significantly less than that in the extreme degradation grassland. Urease activity had significant difference only at 10-20 cm soil layer among the degraded grassland. At 10-20 cm ,20-30 cm soil layer,the activity of catalase and dehydrogenase was increased with the increasing of grasslan degradation degree.But urease and invertase activity were degressive. [Conclusion]Therefore, when monitoring the evolution of soil quality of degraded grassland, the sensitive soil biological indicators are: bacteria, actinomycete, alkaline phosphatase, dehydrogenase, invertase.