Abstract: In order to explore the diversity characteristics of bryophytes in typical metaphase developed tiankeng, a field survey was conducted in Chuandong Tiankeng, Guangxi. The results showed that the species diversity of bryophytes were rich, and the dominant groups were obvious. There were 96 species of bryophytes (including subspecies and varieties), belonging to 57 genera, 33 families. Bryophytes were rich and complex in species composition. Unigeneric family and unispecific genus were rich, including 14 families and 40 genera, which accounted for 42.42% and 70.18% of the whole families and genera respectively. The life forms were divided into 8 types, mainly Wefts and Turfs, which had relatively high diversity of life forms. From the upper to the bottom of the Tiankeng, the distribution pattern of life type was from Turfs with drought resistance to wet Fans. The bryophytes had diversity of ecological types, which was divided into 4 types according to the growth substrate, and bryophytes growing on the surfaces of soil and rocks were dominant. On the height gradient, the species richness of bryophytes changed obviously, presenting a decreasing trend of middle > bottom > upper, which was closely related to the heterogeneity of Tiankeng habitat. As a refugia for native plants in Karst areas, the Chuandong Tiankeng also had a great potential to preserve the diversity of non-vascular higher plants (bryophytes). Therefore, it is suggested that such metaphase developed Tiankengs’ ecological system with special negative topography should be protected.

Key words: Bryophytes, diversity, life forms, Chuandong Tiankeng