The present invention provides a peptide, consisting of the amino acid sequence of SEQ ID NO:1 or the amino acid sequence of SEQ ID NO:2, or a pharmaceutically acceptable salt thereof and a use thereof. The present invention can inhibit the entry of beta-amyloid into the brain. In addition, the present invention can be applied more easily with respect to the suppression of the intracerebral function of beta-amyloid and thus is advantageous in having excellent applicability.