Abstract: The phase constitution and grain size of ball-milling Fe-Ni powders with alcohol as well as the lattice parameter evolution were investigated by X-ray diffraction. The condition of ball-milling was taken as follow: the weight ratio of ball to powder is 6:1, and the revolving velocity is 240 r/min. It is shown that the Fe concentration in the Ni fcc phase increases with the increase of the ball-milling time. The fcc solid solution γ(Fe-Ni) is formed after milling 12 h. The a-Fe is separated out gradually from the γ (Fe-Ni) phase above milling 18 h. The fcc γ phase becomes pure again Ni after milling 48 h. With the further increase of the milling time, the lattice parameter of the a-Fe phase decreases. With the increase of Ni atom fraction in the Fe-Ni mixture meanwhile that of fcc phase increases.