The study was conducted to investigate the bacterial pollution in the air environment, water and the barn floor in the dairy cow farms in Binh Thuy district of Can Tho city., The investigated results showed that the rate of E. coli, Staphylococcus aureus presenting ,in the air of the barns were 40 percent, 80 percent respectively with an average density of E. coli was 3.103 CFU/m3, Staphylococcus aureus was 104 CFU/m3. The rate of E. coli, Staphylococcus aureus in water at the farms were 26.67 percent, 40 percent respectively with an average density of E. coli, was 3.10 exponent 3 CFU/ml, Staphylococcus aureus was 2.10 exponent 3 CFU/ml. The rate of E. coli, Staphylococcus aureus on the barn floor were 86.67 percent, 93.33 percent respectively with an average density of E. coli was 4.104 CFU/1 cm2, Staphylococcus aureus was 4.10 exponebt 4 CFU/10cm2. The Streptococcus agalactiae was not detected in the dairy cow barns of the households at the investigating areas.