An anti-glypican 3 antibody with modified sugar chains, more specifically, an anti-glypican 3 antibody lacking fucose is provided. The anti-glypican 3 antibody with modified sugar chains of the present invention may be produced by a process comprising introducing a nucleic acid encoding an anti-glypican 3 antibody into host cells with reduced fucose addition capability, such as YB2/0 cells and cells lacking a fucose transporter. The anti-glypican 3 antibody with modified sugar chains of the present invention has a high level of cytotoxic activity and therefore is useful as a cell growth inhibitor such as an anticancer agent.
