Acute Hepatopancreatic Necrosis Syndrome (AHPNS) caused an emerging epidemic for black tiger shrimp (P. monodon) and white leg shrimp (L. vannamel) raising in Vietnam since 2010 up to date, this epidemic caused heavy loss for the shrimp industry in almost coastal provinces. Recently, Vibrio paraheamolyticus carrying a phage has been identified as a cause agent of this epidemic. However, further study to find out what phage and other cause agents/reasons of this epidemic is still needed to carry out continuously. In order to determine the epidemiology characteristics of the AHPNS epidemic, a survey using method of cross-sectional study was implemented in Soc Trang province in 2011. A total of 5.966 questionnaires were used for survey in 26 communes of Tran De, My Xuyen and Vinh Chau districts which covered the area of 8.976,85 ha (accounting for 13.09 percent of total shirmp production area of 26 communes). The surveyed result showed that over 50 percent of the surveying shrimp production area was infected with AHPNS. Both Penaeus monodon and Litopanaeus vannamei were infected with AHPNS. The highest infection rate was at 26 - 30 days after stocking. AHPNS epidemic was occurred mainly in the period from March to July.