The aim of this study was to identify the effects of leaf litter decomposition on bacterial community structure in the leaf litter of different tree species in Mount Tai.Four different dominant tree species Robinia pseucdoacacia (RP), Quercus acutissima (QA), Pinus tabulaeformis (PT), and Pinus densiflora (PD) in a Yaoxiang Forest Farm were examined. Illumina high-throughput sequencing of the 16S rDNA genes was performed to analyze the effects of leaf litter decomposition on the bacterial community structure of four dominant tree species in Mount Tai. The results showed that:(1) leaf litter decomposition rates differed significantly among the four species(P < 0.05). In all treatments, RP leaf litter was obviously decomposed faster than other three tree species(P < 0.05). The sequence of decomposition rate was RP > PD > PT > QA. (2) After 1 year of decomposition of the four leaf litters, there was a significant difference between the current chemical element content and the initial content. Carbon and lignin contents were significantly decreased (P < 0.05), whereas nitrogen and phosphorous contents were significantly increased (P < 0.05). (3) A total of 643440 valid sequences were obtained for all samples, which were classified from phylum to genus in accordance with QⅡME, and included 35 phyla, 92 classes, 121 orders, 246 families, 410 genus, and 206 species. The NMDS β-diversity analysis of the bacterial community showed that there was a significant difference between all species, except for PD and PT. At the phylum level, a total of four phyla were dominant (> 5% across all treatments). Based on the average relative abundance, the most abundant phyla were Proteobacteria, Actinomyces, Bacteroidetes and Acidobacteria, although significant differences between the four treatments were found (P < 0.05). At the class level, a wide range of classes dominated. Based on the average relative abundance, the most abundant classes were Alphaproteobacteria, Betaproteobacteria, unidentified-Actinobacteria, Sphingobacteria, Gammaproteobacteria, and Deltaproteobacteria. Unidentified-Actinobacteria and Sphingobacteria were significantly different among the four treatments (P < 0.05). At the species level, Bradyrhizobium elkanii and Luteibacter rhizovicinus were the dominant species after all four treatments, each of which had its own dominant species. (4) There was significant difference between the average number of four-treated observed species, ACE and phylogenetic diversity (PD) (P < 0.05), and these numbers in broad-leaved species were obviously higher than those in coniferous species. (5) Non-Metric Multi-Dimensional Scaling (NMDS) analysis on leaf litter characters and bacterial communities showed that the diversity of bacterial communities was affected by the chemical properties of leaf litter, especially the initial C/N ratio and lignin/N ratio of the litter; In addition, between the two factors of bacterial community diversity and leaf litter chemistry, the decomposition rate was more correlated with the chemical properties of leaf litter itself. The results of this study can improve understanding of the effects of bacterial community structure and diversity on decomposition of leaf litter in forest ecosystem.