Abstract: The study shows that the quantity of soil microorganisms and the activity of soil enzymes are related with crop kind and soil organic matter content. Rice soil has the highest quantity of microorganisms,and herbage soil has the lowest one. The number of microorganisms is much higher in 0～10cm than in 20～30cm soil layer. Protease and urease have a much higher activity in rice soil than in beer, herbage and wheat soils. Catalase activity isthe highest in beer soil, but the lowest in herbage soil.

Key words: Soil microorganism, Soil enzyme activity, Saline-alkali soil, chronosequence, Cunninghamia lanceolata, nutrient status, water use efficiency