White spot syndrom (WSS) is a disease that has caused high shrimp mortality in a short period and severe damage to shrimp culture industry up to date. The purpose of this study was to comprehensively investigate the virus carrying conditions of wild Fenneropenaeus chinensis in Yellow Sea and Bohai Sea. Four spawning ground populations of P. chinensis collected from Yellow Sea and Bohai Sea in 2001 were examined by nested- PCR ( polymerase chain reaction) for the detection of white- spot syndrom virus ( WSSV) . The virus positive rate of the several populations were : the south coast of Korea population 55% ; Bohai Bay population 35%; Liaodong Bay population 94. 7% and Haizhou Bay population 47. 4%, respectively . As a result, the several populations were all carrying WSSV at different levels. Among those, Liaodong Bay population shows the highest WSSV infective rate, which is significantly higher than those of other populations. It may be due to the severe environmental problems and geographical conditions of the bay . Furthermore, the releasing of hatchery seedlings which may carry WSSV during culturing could be related to prawns. high WSSV infective rate. However, the effects of wild shrimp carry ing virus on the shrimp culture industry were obvious and sho uld not be ignored. Therefore, it can be concluded that the establishment of the specific pathogen free( SPF) and specific pathogen resistance ( SPR) cultured population was the only way to avoid the outbreak of the disease, which may be induced by the virus carried by shrimp. At the same time, something should be done to deal with the pollution in order to decrease the inducement that leads to the o utbreak of virus disease. In this study, a method for the detection of WSSV by PCR was developed, a high sensitivity about 1pg WSSV DNA could be seen with nested- PCR, which provided an effective method to diagnose WSSV ahead of time.