“Lumpy Jaw”of kangaroos in zoos is an oral inflammation syndrome caused by alveolus infection，which was characterized by refractory periodontitis，ulcerated gums resulting in ulcer and sinus，swelling and necrosis in maxillofacial region and irreversible malposition of maxillary and mandible seriously. In this study，the pathogens of “Lumpy Jaw” in park kangaroos from Nanjing Hongshan Forest Zoo were isolated and identified. Three strains of bacteria were isolated and were identified as Enterococcus faecalis and Klebsiella pnenmoniae，respectively，by their morphology，cultural characteristics，biochemical characteristics and drug sensitivity. By full-automatic analysis of drug sensitivity and pathogenicity in mice experiment，further identification of the isolated strains were carried out，and the results were consistent with the former. The oral infection of mice experiment showed that the symptoms of “Lumpy Jaw” in the mice could be simulated，but general dozes could not contribute to death of mice.