Abstract: 25 diseased dairy cows that were diagnosed as endometritis were selected from some cattle farms of Jixi Region in Heilongjiang Province. And 39 strains of bacteria were isolated from the 25 diseased dairy cows, among which there were 17 strains of Escherichia coli, 13 strains of staphylococcus, 5 strains of streptococcus and 4 other strains. The drug tolerance test showed that E. coli, staphylococcus and streptococcus were sensitive to ceftriaxone sodium and ceftiofur sodium, and they were comparatively sensitive to gentamicin and tolerant to other several kinds of antibiotics to different extent.