Abstract: To grasp the number and species of bacteria in the surrounding environment of the scaled pig farm and provide the basis for prevention and control of the bacterial disease of pig, the air, drinking and sewage water, faecal and soil samples were collected for bacteriological isolation and identification which from two-scale pig farms in Guizhou province. The results showed that the numbers of bacteria were respectively 1.17×10⁴ to 94.40×10⁴, 0.15×10² to 1.83×10²， 5.00×10⁵ to 32.00×10⁵, 0.46 ×10⁶ to 26.40×10⁶ and 0.30×10⁵ to 52.30×10⁵ CFU/g in the above-mentioned samples, and of these bacteria, there were mainly Staphylococcus, Streptococcus, Escherichia, Salmonella, Yersinia, Proteus, Pasteurella, Listeria, Bacillus, Clostridium and so on. The results suggested that the numbers of bacteria in the other samples except drinking water and soil, were in line with requirement of national regulation for livestock and pourty farms, while there were some conditioned pathogen or pathogen，and these investigations provided an important reference data for prevention and control of pig bacterial diseases.

Key words: scaled farm; bacterial number; bacterial species; investigation