Provided are a peptide having a flavor improving effect derived from milk, a flavor improving agent containing the same, and foods or drinks containing the same.The invention relates to a flavor improving agent containing a peptide including the sequence of Val-Pro and/or Leu-Leu-Leu, and foods or drinks containing the same.本發明之課題為提供一種源自乳之具有風味改善作用之胜肽、含有該胜肽而成之風味改善劑、及含有該風味改善劑而成之食品或飲料。本發明係關於含有包含Val-Pro及/或Leu-Leu-Leu之序列的胜肽而成之風味改善劑,以及添加該風味改善劑而成的食品或飲料。