In order to investigate the role and application potential of Terminalia chebula in the prevention and control of livestock and poultry diseases， three species of common pathogenic bacteria， Escherichia coli， Klebsiella pneumoniae and Enterobacter cloacae were selected as test organisms. The inhibition circle diameter and minimum inhibitory concentration （MIC） of T. chebula and 11 other Chinese herbal extracts were compared， the total leakage rate， electrical conductivity， protein concentration in the supernatant， and the effects of T. chebula on the DNA and protein content of bacteria were analyzed. The results showed that T. chebula had stronger antibacterial effect than other Chinese herbs， with larger circle diameter and lower concentration of bacteriostatic. The conductivity and leakage rate of culture supernatant increased. The protein concentration of the supernatant of E. coli and K. pneumoniae significantly increased （P<0.05） after 2-fold MIC T. chebula treatment for 8 h. T. chebula inhibited the protein synthesis of E. coli， resulting in the deletion of a protein with a molecular weight of about 80 ku. However， T. chebula had no obvious effect on protein synthesis of K. pneumoniae and E. cloacae. T. chebula had no significant gel-blocking effect on bacterial DNA， but could degrade DNA. The above results indicate that T. chebula could exert its antibacterial effect by disrupting the permeability of bacterial cell membrane and inhibiting the synthesis of bacterial nucleic acid and protein.Therefore， the rational application of the T. chebula extract is a new idea for the prevention and control of livestock and poultry infectious diseases in China.