Abstract: Based on spatial replacing temporal series, we studied the diversity of the bryophytes in five different natural succession stages in the karst bauxite tailing piles of the Xiaoshanba Bauxite Deposit, Xiuwen County, Guizhou Province. Results showed that:(1) There were 31 taxa of bryophytes belonging to 18 genera and 11 families, of which there were 29 taxa of mosses belonging to 16 genera and 9 families, and 2 taxa of liverworts belonging to 2 genera and 2 families. In the succession stages, the bryophyte life forms were simple, with short turfs the dominant life form, accounting for 67.7%, and the wefts accounting for 32.3%. The bryophyte species composition was monotonous, with many single-species communities, though mixed-species communities gradually increased along the succession stages. (2) The bryophyte indices were different in different natural succession stages, with the Shannon-Wiener Index, Pielou Index, and Abundance Index all lowest (0.196, 0.283, and -1.930, respectively) in the bare rock stage, and the highest (3.470, 1.281, and 2.342, respectively) in the herbosa-boscage stage. The diversity indices then gradually declined (2.128, 0.88, and 1.267, respectively) in the arbor-shrub stage. The Cody Index and Sørensen Similarity Index showed the opposite tendencies. The faster the replacement rate of species, the smaller was the similarity in the two adjacent succession stages. In the five different natural succession stages, the change in bryophyte diversity demonstrated a regular tendency, whereby the level of diversity increased at first, then decreased gradually on the karst bauxite tailing piles. Generally, the level of bryophyte diversity improved. These findings provide basic information for the ecological restoration and biodiversity conservation of the karst bauxite mining area.