Several samples of Cu1-xSnx series were obtained by mechanical alloying, including η-Cu6Sn5 alloy which are difficult to prepare by melting method. XRD results show that the solid solution with nanometer size is formed which including definite alloy phase in each ball milling sample. M?ssbauer spectra indicate that the Sn-rich-phase and the Cu-rich phase exist besides the alloy phase. We suggest that in the process of the ball milling, the crystallites of Cu and Sn are nanometerized, at first, and then the interdiffusion of the two kinds of atoms takes place and finally the solid solution is formed including the alloy phase, the α-Sn-rich phase and the fcc-Cu-rich phase.