Abstract: 【Objective】 The purpose of this study was to investigate the drug resistance of Streptococcus agalactiae to antibacterial agents and determine the carrying status of virulence gene and drug resistance gene of Streptococcus agalactiae. 【Methods】 In this study， microdilution broth method and common PCR were used to detect the resistance of 16 kinds of antibacterial drugs and related drug resistance genes and virulence genes of Streptococcus agalactiae from bovine. Moreover， the expression levels of 8 virulence genes in different strains were analyzed by fluorescence quantitative PCR. 【Results】 （1）The sensitivity of Streptococcus agalactiae to 11 drugs was more than 65%， among which the highest sensitivity was florfenicol （92.4%） and ceftiofur （88.4%）. The resistance rate of Streptococcus agalactiae to ampicillin， erythromycin and clindamycin was more than 50%， and the resistance rate of Streptococcus agalactiae to sulfagan was more than 45%. （2） The detection rates of gyrA， sul1， ermb and ermc were 100%， 86.67%， 93.3% and 33.3% respectively， while erma， sul2， sul3 and parc were not detected. （3） The detection rates of virulence genes pavA， cfb， fbsA， bibA， cspA， sip， iagA， hylB， rib， bca and cylE were 100%. The detection rates of rib， bca and cylE were 13.3%， 53.3% and 73.3%， respectively. However， the bac， lmb and scpB were not detected. （4） Fluorescence quantitative analysis showed that the expression levels of virulence gene was significantly different among different strains （P<0.05）. 【Conclusion】 The resistance rate of Streptococcus agalactiae to erythromycin and clindamycin is high. The virulence factor of Streptococcus agalactiae is an important factor of host infection disease.