Strawberry (Fragaria x ananassa) is the most widely cultivated small berries in the world. They are not only delicious, juicy, and nutritious, but also have important economic value. However, current research on endophytic bacteria related to strawberry is limited. This work provides a comprehensive description of the composition and diversity of bacterial communities in three niches (root, stem, and leaf) of three strawberry cultivars (White Elves, Tokun, and Akihime). This study indicated that the diversity and composition of strawberry bacterial communities differ significantly between the belowground niche (roots) and aboveground compartments (stems and leaves). The bacterial diversity and richness varied between niches for all three cultivars; and it significantly decreased from root to stem to leaf. The richness and alpha diversity of Akihime bacterial community were significantly lower than that of White Elves in the stems and leaves. Beneficial bacterial genera, such as Ochrobacter, Bradyrhizobium, Sphingomonas, and Pseudolobrys, were more abundant in White Elves and Tokun than in Akihime, especially in roots and stems. The results of this study provide an important reference for discovering new species or genetic variations to improve host fitness and stress tolerance. Further research is needed to uncover the interactions between plants and endophytic bacteria, as well as the potential for extracting bioactive compounds from these bacteria.