Functionally Graded Material (FGM) is a characteristic material having many functions and possibilities. The improvement of the long term stability is strongly necessitated by railway polymeric materials. To carry out the purpose, FGM is an expected material that enables to improve the certain properties and affinities. The authors tried to produce a graded compound of the magnetic particles in the polymer matrix in the magnetic field. From the results, the graded compound of the magnetic particles was produced by the control of magnetic flux. In particular, the control of time during which the magnetic field was charged was effective to improve the dispersion state of the magnetic particles in polymer matrix.