The invention relates to the field of medicaments, in particular to a polypeptide which has the effects of inhibiting metal prolease-9 and tumor necrosis factor liberase and relieving the damage of an acute inflammatory reaction on an organism. The sequence of the polypeptide is Pro-Arg-(D-Cys)-Bip-Arg-Gly-Glu (Bip is D-type diphenyl alanine, D-Cys is D-type cysteine), which is a brand new sequence. The polypeptide can be used for inhibiting the activities of the substrate metal prolease-9 and the tumor necrosis factor liberase on 1 micromole level in vitro and increasing the survival rate ofan endotoxic shock mouse in an in-vivo test, and has a potential new medicament development value.