Background　Histone is a basic structural protein of eukaryotic chromatin. It is released into the extracellular and become the extracellular histone during tissue damage or cell necrosis. Recent studies have found that extracellular histones have an important role in triggering and exacerbating inflammatory injury as danger signal molecules or inflammatory mediators.　Objective　To review the recent researches on extracellular histones for the further studies on the post-traumatic inflammatory response mechanisms of extracellular histones.　Content　Laborate the structures， biological functions and the sources of the extracellular histones and investigate the possible role and mechanisms of the extracellular histones in the post-traumatic inflammatory response from the aspects of sepsis， liver injury， lung injury， kidney diseases， treatments of anti-histones and others.　Trend　Further studies on extracellular histones may find new therapeutic targets and provide theoretical basis for the treatment of sepsis and other inflammatory diseases.