土壤微生物总数及细菌、真菌数量、土壤酶活性（特别是蛋白酶、磷酸酶和蔗糖酶）及土壤养分状况（主要是有机质含量）从杉木幼龄林到中龄林随着林冠的郁闭，林下植被盖度急剧下降，呈明显下降趋势；土壤微生物总数，细菌总数，蛋白酶，磷酸酶，蔗糖酶以及土壤有机质从中龄林到成熟林随着林木密度及郁闭度下降，林下植被盖度逐步得到恢复，也呈明显的上升趋势。由于过氧化氢酶和多酚氧化酶活性的降低，有可能导致中龄林土壤中多酚类有毒物质的积累，这或许是杉木连栽产量下降或成活率低的原因之一。 The total number of soil microorganisms and the number of bacteria and fungi, soil enzyme activity (especially protease, phosphatase and invertase) and soil nutrient status (mainly organic matter content) The coverage of lower vegetation decreased sharply, and the trend was obviously descended. The total amount of soil microorganism, total bacteria, protease, phosphatase, invertase and soil organic matter from middle-aged forest to mature forest decreased with the decrease of forest density and canopy density. Gradually recovered, also showed a clear upward trend. Due to the decrease of catalase and polyphenol oxidase activities, it is possible to cause the accumulation of polyphenolic toxicants in middle-aged forest soil, which may be one of the reasons for the decline of continuous plantation or low survival rate of Chinese fir plantation.