In this study, the less (LR) and more (MR) weathered rock samples and the adjacent red soil samples (SS) were collected from Dongxiang County, Fuzhou, Jiangxi Province to compare the differences in diversity, structure and ecological functions of bacterial communities by applying the high-throughput sequencing of partial bacterial 16S rRNA genes, a metabolic profiling technique (Biolog EcoPlate) and bioinformatics analysis. It was found that as rock weathering degree intensified, the number of unique OTUs and 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%-9.2%) and Proteobacteria (18.8%-34.6%) were the most dominant phyla in these habitats, the relative abundance of Acidobacteria increased, while the relative abundances of Actinobacteria and Alphaproteobacterium decreased. pH, the contents of organic matter (OM), 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 abundances of genes encoding carbonic anhydrase (CA), flagella synthesis and organic acid production in the three groups of samples were in the order of SS>MR>LR, with LR having the highest relative abundance of iron producing carrier related functional genes. In conclusion, as the degree of rock weathering intensifies, α-diversity of bacterial community on tuff surface increases, and the community structure changes significantly changes. Bacterial communities inhabiting rock surface might simultaneously weather tuff in multiple ways. 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.