Abstract: According to the field investigation and analysis of the Osmunda vachellii populations and communities from Mount Maluanshan in Shenzhen，the results indicated that：82 species of vascular plants， belonging to 48 families and 69 genera were found in the O.vachellii community，the floristic components of community was with an south subtropical property; The analysis for the age structure of the community showed that the main dominant species were stable populations，but the frequence index of community was A＞B＜C＞D＞E，which was different from the Raunkiaer’s frequency law，and was also different from those of montane rainforest of Hainan island; The percentage of tree height and individual number from O.vachellii population showed that those with a tree height 0.3-0.7 meters occurred a higher proportion，indicating the populations was in a bloom of development period；and the Simpson and Shannon-Wiener index of diversity is 16.42 and 4.56，while the evenness index for E and E′ is 0.33 and 0.83, respectively，which indicated the diversity and evenness index is closed to those of the climax community from typical subtropical evergreen broad-leaved forest. The study reveals the natural survival state of O.vachellii and provides protection and utilization data for O.vachellii.

Key words: Shenzhen city, Mount Maluanshan, Osmunda vachellii, community, species diversity