The short hairpin RNA interference sequences targeting CP gene of redspotted grouper nervous necrosis virus were designed by using online designing software of Invitrogen Co.,Ltd.The structure consisted of 19 nt sense strand,-4 nt loop and -19 nt antisense strand.These sequences are synthesized,annealed,and cloned into pENTR^TM/U6 to construct the shRNA interference vectors named pshRNA-124,pshRNA-896 and pshRNA-NNV,respectively.Then the expression vector of pEGFP-CP and each of the three shRNA interference vectors are co-transfected into FHM cells by using Lipofectamine 2000.Then the expression and inhibition of EGFP are observed by using fluorescent microscope.The mRNA expression level of CP gene is anaylised by using real time RT-PCR.The result shows that pshRNA124,pshRNA896 and pshRNANNV all suppress the EGFP expression with inhibitory efficiency of 47%,68% and 51%,respectively.The pEGFPCP gene silencing efficiencies of pshRNA-124,pshRNA-896 and pshRNA-NNV at mRNA level are 60%,96% and 55%,respectively,significantly higher than that of control(P<0.05).It demonstrates that all of the three shRNAi vectors have interference effects and can interfere with the expression of EGFP,of which pshRNA-896 is the best one.The result above suggests that shRNAi vectors targeting CP gene of redspotted grouper nervous necrosis virus has been successfully constructed,which will be a basis for further study of the function of CP gene with RNAi technique.