A pathogenic bacterium was isolated from the diseased Procambarus clarkiin Qianjiang,Hubei Province.The strain was identified by physiological and biochemical assay,16S rRNA sequencing and phylogenetic analysis.Then susceptibility of the strain to antibiotics was performed by the agar diffusion method,and the minimum inhibitory concentrations (MICs) were evaluated by the microdilution method.The results showed that the physiological and biochemical characteristics of the isolated strain were similar to that of Klebsiella pheumonia.The 16S rRNA sequencing and phylogenetic analysis showed that the 16S rRNA sequence of the strain shared over 99% similarities with that of K. pheumonia.Therefore,the strain was identified as K.pheumonia.According to the susceptibility results,the strain was sensitive to cefotaxime and polymyxin B among all the tested antibiotics.These results above indicated that the strain was a multiresistant K. pheumonia strain.