In conclusion, 13,969 high-quality ESTs generated from postlarvae of Penaeus monodon in this study provide a rich source for comparative analysis of normal and WSSV-infected shrimp’s biology. EST-based strategy not only greatly facilitates in silico expression profiling and elu-cidating WSSV pathogenesis, but also reveals shrimp’s response to the virus infection. This study may be of importance in a systematic view of regulation between shrimp hosts and WSSV.