The present invention provides a qualitatively-stable functionally gradient material precursor having gradient material composition, as well as a production method of the functionally gradient material precursor, at low cost. Further, the present invention provides a functionally gradient material having gradient material composition, or having both gradient material composition and gradient porosity, so as to achieve high-functionality; as well as a production method of the functionally gradient material. A functionally gradient material precursor is formed by the steps of: forming plural kinds of metal foam precursors, each obtained by performing heat treatment on a metal member so that a plurality of pores are generated within the metal member, by making the material composition of the metal member different; and friction stir welding the plural kinds of metal foam precursors. Further, a functionally gradient material is formed by performing heat treatment on the functionally gradient material.