A polypeptide containing an antibody Fc region variant which has an amino acid sequence in which an amino acid alteration at position 238 according to EU numbering is combined with other specific amino acid alteration(s), was found to have decreased binding activities to all activating Fc³Rs, in particular Fc³RIIa (R type), while maintaining its Fc³RIIb-binding activity, when compared to a polypeptide containing a native IgG Fc region.
