Two RAPD fragments of Siniperca chuatsi virus ( SCV) genome DNA recovered from agrose gel were inserted into plasmid pUC19 ( called SCVE369 and SCVE450) . The sequences reported the length of cloned f ragments were 369bp and 450bp. It doesn.. t show signif icant homology sequences against to those in GenBank. According those sequence two oligonucletide primersets ( P1/ P2 and P3/ P4) were designed and used to amplify genome DNA of SCV by the method of Polymerase Chain Reaction ( PCR) . The results showed primer ( P1/ P2) could specially amplify 369bp in size.. s fragment in SCV genome. Furthermore, this primer set was used to test the DNA samples including the normal mandarin f ish, cultured f ish naturally infected w ith SCV and the fish artif icially infected by SCV. The 369bp in size PCR product was only obtained in the mandarin fish carried SCV. Primer ( P1/ P2) can been used to diagnose SCV disease of mandarin f ish.