Abstract: In Indonesia, the largest distribution of peatlands is found in Sumatra, Kalimantan and Papua, which cover an area of around 14.9 million hectares. Rural communities in Borneo who live in peat swamp areas and tidal areas generally have difficulties in obtaining clean water, especially during the dry season, so that people in Borneo used surface water in the form of peat water. Peat water does not require for daily use such as brushing teeth because it has a low pH, brownish red color and high organic content. The quality of water suitable for use in tooth brushing have to require physically, chemically and microbiologically. Microbiological requirements should be free from pathogenic microbial that cause disease, especially diseases in the oral cavity.: This study used Explanative descriptive method. Peat water samples were taken in the Gambut sub-district, Banjar Regency, South Kalimantan using a sterile bottle that was put into Cary-Blair as Transport medium then put into a coolbox and taken to the microbiology laboratory for identified. Rough colony have identified. Color of colony were white (nutrientagar), white-transparent (Man Rogosa medium) and yellow (Mannitol Salt Agar). Gram staining obtained bacteria in the form of bacilli and cocus. Biochemical tests were found Bacillus sp., Lactobacillus sp and Staphylococcus aureus. The bacteria identified in the peat waters of the Peat District of Banjar Regency are Bacillus sp., Lactobacillus sp and Staphylococcus aureus.