Abstract: This paper deals with the species diversity of pteridophytes from the Laojun Mountain Nature Reserve based on taxonomic and floristic studies. The results show: (1) Richness in pteridophytes species demonstrated by the following large species diversity indices, Dmg index 17.9, Dmn index 2.1, Dri index 41.1 and Dsi index 0.98; (2) High species density (0.02 species / m2) and high individual density (0.6 individual / m2) of pteridophytes; (3) The species occuring most frequently are Alsophila costularis (50.0), Egenolfia appendiculata (50.0) and Polypodiodes amoena (50.0); (4) The species with the largest relative abundance is Tricholepidium maculosum (5.2); (5) Great morphological diversity and variations in size of pteridophytes; (6) The taxa are relatively complete and diversified in phylogeny; (7) The geographical elements are complexity and outstanded by mountainous endemic species of Tonkin Gulf of SE. Yunnan; (8) Ecological diver-sity.

Key words: Pteridophytes

摘要： 本文在分类和区系的基础上，对老君山自然保护区蕨类物种进行多样性研究。结果如下：(1)蕨类物种丰富，物种多样性指数较高；（2）物种密度及个体密度均较大；（3）频度最大的物种为中华桫椤等；（4）相对多度最多者为斑点毛鳞蕨；（5）物种形态各异，大小差别悬殊；（6）分类群比较齐全而且其系统演化的位置多样；（7） 地理成分复杂但以北部湾或滇东南山地特有成分最突出；（8）各种生态类型兼备。

关键词: 蕨类植物, 物种多样性, 自然保护区, 老君山, 滇东南