Since the fatigue life time is a serious problem of the Cu-Al-Ni alloy, it is difficult to apply for practical use. The authors have investigated the influence of the cooling condition of liquid-quenching on fatigue property. The liquid-quenching is performed by a piston-anvil apparatus. It is easy to control the solidification condition. The fatigue life time increases with increasing the cooling rate. The long life time is due to the small grain size, the small volume of γ1' phase, the low density of lattice defects and the low transformation temperature.