Abstract: To investigate the serotype and drug resistance of the Escherechia coli (E.coli) isolates from diarrheic sika deer in peripheral areas (Yushu, Nongan, Jiutai, Shuangyang, Dehui) of Changchun City, Jilin Province. After isolation, cultivation and biochemistry response, a total of 127 strains were isolated; the serotypes of which were definited by slide agglutination, and the susceptibility to 15 antibacterials was determined by plate diffusion and broth microdilution test; 9 drug resistance genes were detected by PCR. 84 strains were determined to be 36 different O serotypes, among which 47 strains distributed in 11 O serotypes: O2, O7, O9, O21, O26, O87, O126, O128, O138, O142 and O154; drug resistance to 15 antibacterials appeared in different degree; strB、strA、aadA、tetA and sul2 were the most prevalent. The drug resistance to sulfanilamide and tetracycline was severe, and the most strains were multidrug resistant; whereas the sensitivity to amoxicillin and kanamycin had the guidance significance for clinical medication.