A study was made on 12 soil biochemical activities in three degenerated grasslands (Dasiphora fruticosa shrub, Kobresia Pygmaea meadow and Festuca sinensis grassland) of the northwestern Sichuan in China. Results show that the soil biochemical activities and the correlations among them were influenced significantly by the degree of grassland degeneration. Soil biochemical activities, especially cellulose de-composition, nitrogen fixation and protease activities, in the grasslands decreased with the degree of grassland, though the differences carer not statistically significant. But the correlations among biochemical activities of the soils were significantly correlated with the degree of grassland degeneration. The worse degrnerative grassland, Festuca sinensis grassland showed no such significant correlations among the 12 soil biochemical activities. Based on the research results considered that the measures for the improvement and amelioration of degenerated grasslands should be adopted according to the soil ecological changes and the correlations among soil biochemical activities.