Abstract: In the present study were studied microbiological qualities of drinking water obtained of Sivas. A total of 100 water samples (once week, during six mounth), collected from ground water and 3 tankers filling from same ground water in spring and summer (March-August), were used as material. The samples were evaluated microbiologycal (total mezophile aerobe bacteria, enterobacteria and E. coli). According to the analysis results; all of the examples were found total mezophile aerob bacteria. The enterobacteria in samples were detection between <10- 103 cfu/ ml. The sample of 12 was analyzed E. coli. Results of, microbiological analysis of the water sources performed at regular intervals for public health. Because, it is very important to transmitted by water diseases. This is the first step of the protective precautions.