Bacteria play an important role in mineral weathering, elemental geochemical cycling, and soil formation. However, there are currently few reports on the structure and function of bacterial communities inhabiting surface of tuffs with different degrees of weathering. The less (LR) and more (MR) altered rock samples and the adjacent red soil samples (SS) from Dongxiang County, Fuzhou, Jiangxi province (China) were collected to compare the differences in diversity, structure and ecological functions of bacterial communities inhabiting rock (soil) surfaces, by applying the high-throughput sequencing of partial bacterial 16S rRNA genes, a metabolic profiling technique (BIOLOG ECO plates), and bioinformatics analysis. It was found that as the weathering degree of the tuff intensified, the number of unique OTUs and the Chao1 index of bacterial communities, as well as microbial carbon utilization and metabolic diversity Shannon index, gradually increased. Acidobacterium (with relative abundance of 17.8-40.7%), Actinobacteria (9.2-29.2%), and Proteobacteria (18.8-34.6%) are the most dominant phyla in these habitats. As the weathering degree of the tuff intensified, the relative abundance of Acidobacteria increased, while the relative abundance of Actinobacteria and Alphaproteobacterium decreased. The pH and contents of organic matter (OM) as well as available P, K, and Ca of rock (or soil) samples explained 99% of the community structure variation of tuff (or soil) surface bacterial communities. The prediction results of bacterial community function by PICRUSt2 showed that the relative abundance of genes encoding carbonic anhydrase (CA), flagella synthesis, and organic acid production in the three groups of samples was SS>MR>LR, with LR having the highest relative abundance of iron producing carrier related functional genes. In conclusion, as the degree of weathering intensifies, the alpha diversity of the bacterial community on the surface of the tuff increases, and the community structure undergoes significant changes. Bacterial communities inhabiting rock surface might weather tuff in multiple ways simultaneously. Additionally, microbial communities inhabiting tuff surfaces with different weathering degrees had different priority utilization patterns for different carbon sources. The present study further enriched the changes in microbial community structure and function during the weathering process from tuff to red soil.