Abstract:To reveal the seasonal dynamics of enzymes activities and the relationship with nutrients, the soil physical and chemical properties, enzymes activities for different seasons of the masson pine pure forests and Chinese fir mixed forests in the Three Gorges Reservoir Area were studied.The results showed that the minimum activitiy values of invertase, urease, polyphenol oxidase, catalase and cellulose were both found in winter, and the maximum were found in autumn except for polyphenol oxidase in summer.The same trend of seasonal variation of enzymes activities was found between invertase,urease and catalase, and it showed that the enzymes activities increased then decreased and then increased again from the summer to spring.Except polyphenol oxidase, the activities of other four enzymes had a significant positive correlation with soil organic matter, total nitrogen, soil water content, nitrate nitrogen.Significant positive correlations were found between the four enzyme activities.