Abstract: The present invention provides a peptide represented by formula (I) of X1-Leu-X2-Leu-X3 wherein X1 represents Glu or Asp, X2 represents His, Lys or Arg, X3 represents Asp or Glu, with Glu, Asp, Leu, His, Lys and Arg being respectively glutamic acid, aspartic acid, leucine, histidine, lysine and arginine; or a pharmaceutically acceptable salt thereof; a composition for the treatment or prevention of at least one selected from cartilage damage and arthritis, containing the same peptide or a pharmaceutically acceptable salt thereof as an active ingredient; and a composition containing the same peptide or a pharmaceutically acceptable salt thereof and TGF?1.