Based on the Cu-Zr-Ti ternary phase diagram,four sets of Cu-Zr-Ti multilayered films with various compositions of Cu20Zr36Ti44,Cu36Zr31Ti33,Cu49Zr24Ti27,and Cu67Zr16Ti17 were prepared and then the ion beam mixing was carried out.It turned out that the increase of Cu content doesn’t always have a positive effect on the glass forming ability.The glass forming ability of Cu49Zr24Ti27 was degraded due to the appearance of a Cs Cl-type B2 structure Cu Zr phase in the eutectic region.The experimental observations justify the existence of the Cu Zr phase under the non-equilibrium condition.Possible formation mechanisms for the crystalline phase were also discussed in terms of the atomic collision theory. Based on the Cu-Zr-Ti ternary phase diagram, four sets of Cu-Zr-Ti multilayered films with various compositions of Cu20Zr36Ti44, Cu36Zr31Ti33, Cu49Zr24Ti27, and Cu67Zr16Ti17 were prepared and then the ion beam mixing was carried out. It turned out that that the increase of Cu content does not always have a positive effect on the glass forming ability. The glass forming ability of Cu49Zr24Ti27 was degraded due to the appearance of a Cs Cl-type B2 structure Cu Zr phase in the eutectic region. justify the existence of the Cu Zr phase under the non-equilibrium condition. Possible formation mechanisms for the crystalline phase were also discussed in terms of the atomic collision theory.