Material characteristics that a foamed filler material (s) to be filled in a frame cross section (fr) should have are discussed. By using a material complying with the characteristics, the energy absorbability of the frame (fr) is effectively enhanced. In a frame structure (fr) for vehicle bodies in which a filler material is filled in at least part of the cross section of a frame, the filler material is set to a mean compressive strength of not less than 4 MPa and/or a maximum bending strength of not less than 10 MPa. More particularly, the filler material is set to a mean compressive strength of not less than 5 MPa and/or a maximum bending strength of 60 MPa.