Objective This investigation aimed to examine how buccal mucosa microbiome succeeds in a healthy population with different ages and dentition stages. Methods Twenty-five subjects were recruited and subdivided into five groups: pri-mary dentition group, mixed dentition group, adolescent group, adult group, and elderly group. Individual mucosal microbiota was obtained by gently scraping both sides of the buccal mucosa with a cotton swab. Microbial diversity was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results 1) The composition of buccal mucosa microbiota has great intra-individual divergence. 2) The average band numbers of the primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group were 21.2±4.0, 17.8±3.9, 15.8±4.3, 16.8±3.7, and 22.2±6.5, respectively. No between-group differences was observed (P>0.05), indicating that predominant strains in the oral cavity may be stable throughout an individual’s lifetime. 3) The Shannon indices of primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group were 1.73±0.2, 1.43±0.1, 1.05±0.2, 1.45±0.2, and 1.63±0.3, respectively. A significant between-group difference was observed (P=0.003), indicating that the microbial diversity of the buccal mucosa decreases from childhood through adolescence, but increases from adult through senescence. 4) The clustering analysis showed that most of the samples in the same group clustered together, indicating higher intra-group community structure similarity. Conclusion Composition of the buccal mucosa microbiota was different among age groups. Adolescence may be an essential turning point of microbial ecology succession throughout life.