Abstract: C-type lectin (CTL) is an important innate immune factor that plays an important role in the immune defense of prawns. The gene expression was detected with relative quantitative PCR, the virus number was detected with absolute quantitative PCR, and the number of infected cells was detected with histology analysis. The data showed that the expression of LvCTL1 was significantly upregulated with WSSV challenge; the expression of WSSV envelope protein VP28, virus loads and the number of infected cells of stomach epithelium in LvCTL1 knockdown prawns upon WSSV infection were significantly higher than those under the dsEGFP control. These results indicated that LvCTL1 expression was significantly activated with WSSV challenge and played a role in WSSV replication inhibition.