Mg60Cu16Ni10Nd14 bulk amorphous alloy with a diameter of 5 mm was prepared by copper mould casting. Its microstructure, phase structure and thermal stability were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The results show that the alloy is completely composed of amorphous phase, and phase-separated regions are homogeneously distributed in the as-cast sample. The glass transition temperature Tg and the crystallization temperature Tx of the alloy are 431 and 488 K, respectively, and the temperature interval of the supercooled liquid region ?Tx is 57 K, which means the quaternary amorphous alloy has great glass forming ability. The compressive test shows that the fracture strength of 653 MPa and the plastic elongation of 2.5% are obtained. The good plasticity is because of lots of dimples on fracture surface.