Five shRNAs targeting different sites in white spot syndrome virus (WSSV) genome,respectively designated as RR9,RR1,DP1,DP2 and PK1,were designed and constructed.Followed by WSSV infection,each of which was introduced into Litopenaeus vannamei shrimp by injection.The result demonstrated that both the proliferation of WSSV in vivo and the shrimp mortality were decreased in different degrees in all of the shRNAs-treated groups.Based on the analysis,the RR9 targeting WSSV ribonucleotide reductase gene had the best protective effect against WSSV,which would be used for a further research on anti-WSSV by RNAi.