AnnotationofthegenomesequenceoftheSARS-CoV(severeacuterespiratorysyndrome-associatedcoronavirus)isindispensabletounderstanditsevolutionandpathogenesis.WehaveperformedafullannotationoftheSARS-CoVgenomesequencesbyusingannotationprogramspubliclyavailableordevelopedbyourselves.Totally,21openreadingframes(ORFs)ofgenesorputativeuncharacterizedproteins(PUPs)werepredicted.SevenPUPshadnotbeenreportedpreviously,andtwoofthemwerepredictedtocontaintransmembraneregions.EightORFspartiallyoverlappedwithorembeddedintothoseofknowngenes,revealingthattheSARS-CoVgenomeisasmallandcompactonewithoverlappedcodingregions.ThemoststrikingdiscoveryisthatanORFlocatesontheminusstrand.Wehavealsoannotatednon-codingregionsandidentifiedthetranscriptionregulatingsequences(TRS)intheintergenicregions.TheanalysisofTRSsupportstheminusstrandextendingtranscriptionmechanismofcoronavirus.TheSNPanalysisofdifferentisolatesrevealsthatmutationsofthesequencesdonotaffectthepredictionresultsofORFs.