Abstract: A strain of bacteria isolated from the feces sample of a bloody diarrhea rhesus monkey was identified to be Citrobater freundii by the Biomerieux methods of ID 32 E，ATB automatic analyzer，id%= 99.9.This strain is sensitive to norfloxacin，ciprofloxacin,cefotaxime,ceftriaxone,ceftazidime, chloramphenicol, and resistive to gentamicin, amikacin，tobramycin, flerox-acin，ampicillin，cephalexin, cefazolin，cephradine，trimethoprim/sulfamethoxazole, tetrecy-cline, and furazolidone by K-B method. So we should pay great attention to Citrobater freuyndii in isolating culture of rhesus feces.