Abstract: The present invention provides a method of intracellular introduction by which a protein and/or peptide can be efficiently introduced into living cells and which makes it possible to effectively analyze the behavior and function of the protein and/or peptide introduced and can be suitably utilized/applied, for example in the technology “live cell imaging” which realizes the immunohistochemical visualization in living cells under physiological conditions. The method of intracellular introduction is a method for introducing a protein and/or peptide into a cell, which comprises the process of introducing a conjugate generated by binding of a compound adsorbable on a cell surface to a protein and/or peptide via a polysulfide bond into a cell and treating with a reducing agent.