Objective To identify the P. mirabilis strain isolated from infant rhesus monkeys in the period of artificial feeding, and provide useful data for detection and identification of the bacteria in laboratory rhesus monkeys. MethodsP. mirabilis strains isolated from infant rhesus monkeys were identified by cultural characteristics, colony morphology, staining, motility and biochemical test and serological test. Meanwhile, antibiotic sensitivity, virulence and toxin tests were conducted.ResultsThe results of cultural characteristics, colony morphology, staining, biochemical and serological tests showed that the isolate was a strain of P. mirabilis. Effective therapeutic drugs were screened by antibiotic sensitivity test, and the disease was effectively controlled. Virulence tests showed that it is a highly pathogenic strain to mice. ConclusionsThe results of this study demonstrate that P. mirabilis isolated from infant monkeys is the pathogenic agent leading to their diarrhea and death. This bacteria strain is a conditional pathogen, which may cause some potential harm to researchers and laboratory rhesus monkeys. Although laboratory rhesus monkeys are allowed to be P. mirabilis carriers in our country, it is worth to pay high attention to the serious consequence of P. mirabilis infection, and it should be considered as an important issue. 