Abstract: A bacterial strain,named HW2018,was isolated from juvenile pearl gentian grouper(Epinephelus fuscoguttatus♀×E.lanceolatus♂) with skin ulcer disease and identified as Vibrio harveyi by morphological observation,physiological and biochemical characteristics and phylogenetic analysis of 16S rDNA sequences.Artificial infection experiment proved that the strain HW2018 was the causative pathogen.Death rate in one week was 100% with the injection dose(3×10⁴ cfu/g) through celiac injection or muscle injection.The drug sensitivity test revealed that V.harveyi was sensitivity to meropenem,ciprofloxacin and levofloxacin,but resistant to ampicillin.