Abstract: The paper deals with the activities and dynamics of four hydrolases and two oxido-reductases in the floor of the subtropical rain forest in Hexi, Fujian province. The hydrodase activities of invertase, protease,urease and acid-phosphatase were 5.08 13.24mg glucose/g dry soil. 37℃. 24h,0.18 0.28mg NH₂-N/g dry soil.30℃. 24h,0.25 0.37mg NH₃-N/g dry soil.37℃. 24h and 0.80 1.51mg phenol/g dry soil. 37℃. 24h respectively, with higher intensity during May-August.The oxido-reductase activities of polyphenol oxidase and catalase were 1.81 3.31ml 0.01NI₂/g dry soil.2min and 12.50 21.89ml 0.1N KMnO₄/g dry woil.20min respectively,with higher intensity during January-March and September(or October)-December. The fluctuation of enzyme activity was in order of invertase>acid-phosphatase>polyphenol oxidase>catalase>protease>urease,There was significant negative correlation between seasonal dynamics of hydrolase activity and oxido-reductase activity. The activities of four hydrolases were significantly and positively correlated with the quantity of fungi and bacteria(except acid-phosphatase), monthly mean temperature,monthly rainfall(except invertase),and total phosphorus in soil.The activities of two oxido-reductases were significantly and positively correlated with organic matter in soil.

Key words: Aurelia spp., life history, environmental factor, jellyfish bloom.