本文从群落及其组成结构等方面分析了闽北长期封禁保护的森林（ｃｏｎｓｅｒｖｅｄｆｏｒｅｓｔ，ＣＦ）和人为干扰后的退化森林（ｄｅｇｒａｄｅｄｆｏｒｅｓｔ，ＤＦ）群落物种多样性，结果认为，ＤＦ群落的植物物种丰富度和ＳｈａｎｎｏｎＷｉｅｎｅｒ指数与ＣＦ群落相近或略高，但ＤＦ群落植物种类组成和层次结构的物种多样性发生明显变化，群落物种种群基础已改变，稀有种和渐危种缺乏，这正是ＤＦ与ＣＦ群落物种多样性的本质差异。 In this paper, the species diversity of long-term conservation forests (CFs) and degradedforest (DF) communities in northern Fujian were analyzed from the aspects of community and its composition. The results showed that DF species richness And ShannonWiener index were similar to or slightly higher than that of CF community. However, the species diversity and composition of plant communities in DF community changed significantly, the speciespopulation base of community had changed, and rare species and disappearing species were lacking. This is exactly what DF And CF community species diversity of the essential differences.