Abstract:In order to detect and identify the pathogen of the skin ulceration disease of Plectropomusleopardus, the bacteria were isolated from diseased fish and identified as Vibrio harveyi basing on morphological characteristics, physiological and biochemical identification as well as 16S rRNA gene sequence analysis. The drug sensitive tests of 18 kinds of antibiotics were carried out using Kirby-bauer way. Results showed that the bacteria were most sensitive to Florfenicol, intermediate sensitive to 6 antibiotics including Cefazolin and Neomycin, and resistant to 11 antibiotics including Carbenicillin and Cefalexin. The minimum inhibitory concentration (MIC) of 4 selected antibiotics were also determined using double dilution method. The result revealed that the Florfenicol showed the best inhibiting effect among the 4 antibiotics and the MIC was 0.5200 μg/mL.