Abstract: The objective of this study was to determine the prevalence of Klebsiella isolates associated with dairy cow mastitis from Shanghai and Hebei regions and to characterize the antimicrobial resistance profiles of the isolates.Milk samples were recovered from the dairy cows with mastitis in Shanghai and Hebei regions and were tested for the presence of Klebsiella strains by traditional isolation and selective cultivation methods.Subsequently,the isolates were phenotypically and molecularly identified.The antimicrobial resistance of the isolates against the commonly used antibiotics in veterinary clinical practice was characterized.Among the 100 milk samples collected from Shanghai region,18 of them were Klebsiella positive,with a separation rate of 18%.For the 100 milk samples recovered from Hebei region,there were 14 milk samples with the presence of Klebsiella strains,indicating an isolating rate of 14%.A higher separation rate of Klebsiella was observed in the latter half of 2017 for both Shanghai and Hebei regions compared to the first half.The Klebsiella isolates expressed resistance to the tested antibiotics in different degrees.The isolates resistant to single one and multiple antimicrobial agents accounted for 21.88% and 53.13% of all strains,respectively.Only 12.50% of the isolates were susceptible to all of the tested antibiotics.Our results demonstrated that the presence of Klebsiella was associated with the emergence of dairy cow mastitis in Shanghai and Hebei regions,and the prevalence of drug resistant isolates were observed.The surveillances for the epidemiological trends and patterns of antimicrobial resistance of Klebsiella in animal production and veterinary clinical practice are urgently needed.Furthermore,prudent used of antibiotics in veterinary medicine is also strongly recommended to restrain the emergence of drug resistant bacteria.