Abstract: A strain of gram-negative bacterium was separated from the lymph node of a diseased pig, which was primarily diagnosed to be infected by Haemophilus parasuis according to the pathological changes. The strain was identified to be Leclercia adecarboxylata according to the physiology and biochemistry characteristics, biochemical analysis by automatic microorganism analyzer, identification results by time-of-flight mass spectrometer, and 16S rRNA sequence analysis, the results with the additional test was also consistent to the characteristics of Leclercia adecarboxylata. In this study, the drug sensitivity and animal pathogenicity of this strain were observed, and the morphological characteristics of the strain on different media were described.