High mobility group box-1 (HMGB1) is an evolutionarily conserved protein,which widely exists in mammals.HMGB 1 contains the nucleus localization sequences.Intracellular and extracellular HMGB1 shows different biological functions.Extracellular HMGB1 is closely related to sepsis,cancer,rheumatoid immune,atherosclerosis,ischemia-reperfusion injury and so on.The mobilization of HMGB 1 from the nucleus to the cytoplasm and subsequent release involves the processes of post-translation modification,active secretion and nuclear localization.