Abstract: A peptide complex including: a peptide; and a cell-membrane-permeability-imparting group introduced into the peptide, wherein the cell-membrane-permeability-imparting group includes a dendritic structure including four or more branches, and at least four branches of the four or more branches include basic functional groups at ends thereof.

Abstract: Novel cell-penetrating peptides are provided, which are excellent in cell membrane permeability. The cell-penetrating peptide or salt thereof according to the present invention is characterized in comprising the sequence represented by formula (I) or the formula (II) as follows: X-(A-B-C)l-(D)m-(Arg)n (Formula I) or X-(Arg)n-(D)m-(A-B-C)l (Formula II), wherein X is a physiologically active peptide, A, B and C are aliphatic amino acids, D is an arbitrary amino acid, l is an integer of 1 or more and 4 or less, m is an integer of 0 or more and 5 or less, when l is 1, n is an integer of 8 or more, when l is 2, n is an integer of 6 or more, when l is 3, n is an integer of 4 or more, when l is 4, n is an integer of 4 or more.