High mobility group protein B1 is a member of the HMGB family consisting of three members, HMGB1, HMGB2 and HMGB3.It Contains 2 HMG box DNA-binding domains entitled box A and box B and It is a highly negative-charged C terminus. As a nuclear protein, HMGB1 stabilizes nucleosomes and allows bending of DNA that facilitates gene transcription which is essential for individual survival. Meanwhile, it is revealed that HMGB1 can also act as a cytokine extracellularlly and regulates monocyte, T cell, dendritic cell activities in inflammatory responses.