A method of modulating the plasma half-life of anti-glypican 3 antibody, a pharmaceutical composition comprising as an effective component the anti-glypican 3 antibody that has a plasma half-life that has been modulated, a method of preparing the anti-glypican 3 antibody and a pharmaceutical composition comprising the anti-glypican 3 antibody as an effective component are provided. Disclosed is a method of modulating the plasma half-life of anti-glypican 3 antibody by modifying an amino acid residue that is exposed on the surface of the anti-glypican 3 antibody and anti-glypican 3 antibody that has a plasma half-life that has been modulated by amino acid residue modification, a pharmaceutical composition comprising as an effective component the anti-glypican 3 antibody, and a method of preparing the anti-glypican 3 antibody and producing a pharmaceutical composition comprising the anti-glypican 3 antibody as an effective component.
