Four soil samples were collected from Huajiang distract to represent four different types of land management,including in forest,abandoned land,cultivated land and Zanthoxylum bungeanumforest.Soil aggregates were obtained with dry sieving method for soil enzyme activity analysis.The results show that in the forest,the large soil aggregates(>5 mm)had the strongest soil enzyme activity,and the microaggregates(< 0.25mm)had the lowest.The aggregates from the abandoned land showed an opposite trend, and the aggregates the farmland and Zanthoxylum bungeanum forest were the intermediate.The sucrose, amylase,urease,protease,and phosphatase of the aggregates of all the three sizes showed the highest activity in the forest,and the lowest in the cultivated land.The catalase activity of the aggregates from the abandoned land sample was the lowest.The amylase activity of micro-aggregates(<0.25mm)was the highest. The aggregates showed the order of decreasing amylase,protease,acid phosphatase,and catalase activities as:micro-aggergats>2~1mm aggregates>large aggregats.With increase of aggregate size,the enzyme activity decreased.The aggregates also showed the order of decreasing polyphenol oxidase and urease activities as:micro-aggregats>large aggregats>2~1mm aggregates.The enzyme activity of soil micro-aggregates of was the highest.The forest had the least content of micro-aggregate.The results indicate that the soil enzyme activity in the forest was relatively low,resulting a slow release rate of available nutrients.On the contrary, the nutrients in the cultivated land were released quickly.