[Objective] To compare oral microbial diversity between periodontitis patients and healthy people by analyzing the saliva microbial community structure in the same region with same nationality. [Methods] We collected 10 saliva samples from 10 subjects (5 from periodontitis patients, 5 from healthy people) and marked DP (Dongxiang periodontitis patients) and DH (Dongxiang healthy people). Saliva samples’ DNA was extracted and the 16S ribosomal RNA gene clone library was constructed. The sequencing results were analyzed by software such as MOTHUR, MEGA 4.0, and ClustalX 3.0. [Results] A total of 115 OTUs (DP 60; DH 75) were obtained and all OTUs were classified into 6 phyla and 27 genera. TM7 was the unique dominant phyla in DP group. The dominant genera in DP group only included: Fusobacterium, Porphyromonas, Peptostreptococcus, TM7_genera. [Conclusion] There is a certain difference of oral microbial community structure between Dongxiang periodontitis and healthy people. The roles of Fusobacterium, Peptostreptococcus, TM7_genera in oral cavity of periodontitis patients may deserve further study.