Acute hepatopancreatic necrosis disease (AHPND), also called early mortality syndrome (EMS) in shrimp was fi rst seen in China in 2009, before it spread to Viet Nam and cause serial death of shrimp in Ninh Thuan in 2010. In this study, we isolated 56 strains of Vibrio sp. from 30 samples of white shrimp were infected AHPND in shrimp ponds in Ninh Thuan. From the result of LD50 testing showed 12 strains of Vibrio sp. has high lethal virulence in which Vibrio sp. NT2.5 has the highest virulence (LD50 = 8.98x10³ CFU / mL). The shrimp disease in this experiment were tested by histological methods. In PCR technique, by using specifi c primers to detect PirAvp and PirBvp toxin genes, 6 Vibrio sp. strains were identifi ed that contain the toxin genes PirAvp and PirBvp, NT 2.5 ; NT2.8 ; NH5.3c ; NH8.4 và NT4.5 have PirBvp gene, NT6a has PirAvp gene. The biochemical methods for identifi cation of 6 strains was perfomed, it homologous over 80% with Vibrio parahaemolyticus. The highest virulent NT2.5 was identifi ed by PCR method, sequencing based on the 16S rDNA region, showed that NT2.5 was identifi ed as Vibrio parahaemolyticus.