The dynamic scaling of phase separation in amorphous Cu12.5Ni10Zr41Ti14Be22.5 alloy has been investigated by means of smallangle neutron scattering. A detailed scaling analysis of the scattering function indicates that the dynamic scaling state of the scattering is reached in the early stage of the phase separation. We demonstrate that the dynamic scaling hypothesis can be applied to the phase separation sequence in deeply supercooled liquid.