It is found that a monoclonal antibody capable of recognizing at least two amino acid residues among amino acid residues located at position-69, position-79, position-81 and position-102 in human midkine has excellent reactivity with human midkine and an excellent activity of neutralizing human midkine. It is observed that the antibody having excellent neutralizing activity as mentioned above also has an activity of inhibiting the proliferation of a tumor. The use of the antibody according to the present invention enables the effective treatment of cancer and the efficient detection or purification of midkine.
