Delegation　mechanism　in　the　TPM　specification　version　1.2has　a　security　problem　that　attackers　can　access　the　resource　of　TPM　using　the　old　authorization　data　and　correlative　delegation　information　which　has　been　revoked.　The　paper　analyses　the　principle　and　security　problem　of　delegation　mechanism　in　the　v1.2　specification　of　TPM,　and　proposes　a　new　delegation　scheme.　In　this　scheme,　TPM　maintains　a　list　which　records　a　mapping　relation　between　authorization　data　and　their　privileges.　Based　on　this　list,　the　creation　and　execution　flow　of　delegation　has　been　improved.　TPM　updates　the　list　synchronously　when　creates　and　revokes　the　delegation　blob　and　queries　the　list　to　judge　whether　the　delegation　blob　is　valid　currently　when　executes　the　delegated　request.　The　results　indicate　that　the　new　delegation　mechanism　is　feasible　and　the　reliability　and　security　of　delegation　model　has　been　improved　by　means　of　this　new　scheme.