The virions of causative virus for white spot syndrome in cultured Fresh shrimp, Penaeus chinensis were rod-shaped, double envelope. An average size of the virion was 70 nm in diameter and $250~300$ nm in length. Histopathological test of affected stomach, heart, and lymphoid organ revealed nuclear hypertrophy. Infectivity trials carried out by injection and feeding with purified virus revealed high cumulative mortality to healthy shrimp. The twenty one different protein species were detected in the analysis of virion. The length of total DNA from the purified virus particles were detected as a single band, double-stranded DNA molecule of approximately 114 kb.