[Objective] In order to find out the etiology and pathogen resistance of diarrhea calves in a large-scale dairy farm in Shandong Province,the pathogenic identification and drug resistance analysis were carried out. [Method] A total of 18 samples of mesenteric,lung,spleen and other tissues of dead calves were collected aseptically and put into sampling bags. Through bacterial isolation and culture and biochemical test,bacterial 16 S rRNA was amplified by PCR and toxin typing was identified. The K-B agar diffusion paper method was used to test the drug resistance of the isolated strains,and 14 drug resistance genes were detected by PCR electrophoresis. [Result] The results showed that 5 strains of C.perfringens type C were detected,and the detection rate was 27.8%. The isolated bacteria showed resistance to a variety of antibiotics,and β-lactams,aminoglycosides,sulfonamides and chloramphenicol resistance genes were detected. [Conclusion] The results showed that C.perfringens type C was the pathogenic bacteria causing diarrhea in calves on dairy farms,and it was resistant to some antibiotics. The results of this study provide a reference for the prevention and control of Clostridium perfringens in dairy farms.

diarrhea calves  /  clostridium perfringens  /  toxin genotyping  /  drug resistance