The present invention provides an oral composition and a method for improving brain function at a low dose. The composition for use in improving brain function comprises Phe-Pro or its salt as active ingredient.本發明係提供改善腦功能用之低用量且可經口攝取之組成物及方法。本發明為以Phe-Pro或其鹽做為有效成分之腦功能改善用組成物。