In order to identify the change of drug resistance of Staphylococcus aureus and Escherichia coli（E. coli）in scale chicken farms before and after the ban on antibiotics，and to evaluate the impact of the use of antibiotics on the farms，the environment of the farms was sampled before and 6 months after the ban，followed by isolation of E. coli and Staphylococcus aureus，then the sensitivity of the two kinds of bacteria to15 kinds of common antibiotics were tested and compared. The results showed that，before the ban，the E. coli isolated was more sensitive to Tobramycin，Lincomycin，Cefradine and Kalamycin，but resistant to Sulfamethoxazole，Oxytetracycline，Cefazolin and Penicillin；while Staphylococcus aureus was more sensitive to Ceftriaxone，Kalamycin，Cefazolin and Florfenicol，but resistant to Oxytetracycline，Sulfamethoxazole，Gentamicin and Tobramycin. Six months after the ban，the two bacteria were increasingly sensitive to most antibiotics to different extent，except to Oxytetracycline，Sulfamethoxazole，Florfenicol and Penicillin，the sensitivity to which was slightly increased or even decreased. In general，the sensitivity of the two bacteria could be improved in farms by the ban，and drug resistance was reduced accordingly. So the prohibition and scientific use of antibiotics could be guided and supported with data in farms.