In order to ascertain the susceptibility and the potential danger of WSSV to the cultured Portunus trituberculatus, the healthy crabs were inoculated with WSSV by intramuscular injection and feeding. The results showed that the crabs in the group of intramuscular injection all became diseased and died at 10 to 16 days after being inoculated; the mortality of the group of feeding was 33%, and that of the control group was 0. Real-time PCR assay was developed in this study for quantitative analysis of WSSV in muscle and hepatopancreas. Detectable rates of WSSV from intramuscular, feeding and control groups were 100%, 50% and 0 respectively. Histopathological observation showed that the nucleus of target cells in the hepatopancreas, atrial muscle, and gill became swollen and distorted, servere vacuolation and necrosis of epithelial cells of hepatopancreas and gill, as well as the atrial muscle fibres were obviously observed. Under electron microscope,virus particles with the same size and morphological features as WSSV were seen in the abnormal tissue cells. In conclusion, the WSSV can infect Portunus trituberculatus and cause obvious histopathological changes in the crab tissues, and additionally, the degree of the infection of WSSV was closely related to the amount of virus, as well as the crab's health and environment conditions.