Inordertoelucidatethemolecularandimmunologicalmechanismsaswellasthepathogenesisofhemorrhagicfeverwithrenalsyndrome(HFRS),theCD8^+cytotoxicTlymphecytes(CTL)clonewasestablisheddirectlyfromperipheralbloodmononuclearcells(PBMC)ofpatientswithHFRS.TheactivitiesofCTLweredetectedasusualwithEBV-transformedlymphoblastoidcellline(BLCL)astargetcells.TheresultsshowedthattheCTLclonecouldrecognizedandkilledthetargetcellswithspecificityofnucleocapsidproteinofHantaanvirus(HTNVNP)withthecytotoxicitypercentagesof50.2%,25.4%and39.0%respectively.TheseresultsdemonstratedthattheantigenicepitopesofHTNVNPmainlylocatedontheC-temainaloftheviralnucleocapsidprotein.