The invention is to provide a metal plate of laminated heterogeneous materials, and an iron core of the same, where a plurality of metal plates of different material qualities are easily and stably joined, have characteristics over many applications, may attain low production cost, and provide a making method thereof. That is, a metal plate of laminated heterogeneous materials, which is joined by laminating a plurality of metal plates of different material qualities, is joined by caulking a first material body of the metal plate of the laminated heterogeneous materials having notches at intermediate parts thereof, as well as caulking projections formed by cutting down rows of both ends thereof in the length direction of the notches, and a second material body of the metal plate of the laminated heterogeneous materials formed with caulking holes for inserting the caulking projections, at the caulking projections of said first material body and the caulking holes of the second material body.