Abstract:By means of species similarity coefficient and species diversity index, the characteristics of species diversity of floor bryophytes in the Baihua Mountain National Nature Reserve in Beijing were studied. The results showed that there were 65 floor species (including subspecies and varieties) belonging to 31 genera of 13 families. Species composition, dominant families and dominant species were different in 8 kinds of vegetation, Pottiaceae and Bryaceae were the absolute families in meadow and shrub, but the Entodontaceae was the most common family in forest vegetation. The species similarity between Pinus tabulaeformis forest and deciduous broadleaved forest was the highest (0.516 3), but meadow and Vitex negundo shrub between mostly forest vegetation were zero. The growth base was the most important environment factor related to the distribution of floor bryophytes, and the humidity, herbage coverage, litter coverage were also related to the distribution of the bryophytes on floor. Betula platyphylla forest and deciduous broadleaved forest were the center of bryophyte diversity and the key area for the bryophyte diversity conversation.