A new kind of coherent segregation would form in the Fe-10% Cr which was proton-implanted at R.T. and was irradiated with electrons at 623 - 723 K. Streak diffraction patterns can be observed at the same time. Such segregations were formed along the directions of ,having a length of about 100 nm and a diameter of about 1-2 atom size. Hydrogen and pure point defects produced by electron irradiation were considered to be the cause of the formation of segregation.