Objective:Tostudytheeffectofmildhypothermiaonglucosemetabolismandglycerolofbraintissueinpatientswithseveretraumaticbraininjury(STBI)usingclinicalmicrodialysis.Methods:Thirty-onepatientswithSTBI(GCS≤8)wererandomlypidedintohypothermicgroup(GroupA)andcontrolgroup(GroupB).Microdialysiscatheterswereinsertedintothecerebralcortexofperilesionalandnormalbraintissue.AllsampleswereanalyzedusingCMAmicrodialysisanalyzer.Results:Incomparisonwiththecontrolgroup,lactate/glucoseratio(L/G),lactate/pyruvateratio(L/P)andglycerol(Gly)inperilensionaltissueweresignificantlydecreased;L/Pinnormalbraintissuewassignificantlydecreased.Incontrolgroup,L/G,L/PandGlyinperilensionaltissuewerehigherthanthatinnormalbraintissue.Inthehypothermicgroup.L/Pinperilensionaltissuewashigherthanthatinrelativenormalbrain.Conclusions:MildhypothermiaprotectsbraintissuesbydecreasingL/G,L/PandGlyinperilensionaltissueandL/Pin'normalbrain'tissues.Theenergycrisisandmembranephospholipiddegradationinperilensionaitissueareeasiertohappenaftertraumaticbraininjury,andmildhypothermiaprotectsbrainbetterinperilensionaltissuethaninnormalbraintissue.