Amorphous powder of Mg-Ni-Y system was prepared by mechanical alloying, and the amorphous bulk was produced by pulsed current sintering. The corrosion resistance was measured by polarization curve of the sintered amorphous specimen. After mechanically alloying of elementary powders for 400 h, Mg₈₀Ni₁₅Y₅ and Mg₈₀Ni₁₀Y₅B₅ were obtained as powder but Mg₈₀Ni₅Y₅B₁₀ are obtained like a fish scale. Mg₈₀Ni₁₅Y₅ powder consisted of amorphous phase and Mg₂Ni compound as the result by XRD and DSC measurements. However, Mg₈₀Ni₁₀Y₅B₅ powder was almost amorphous phase. The bulk amorphous alloys were produced by pulsed current sintering of these amorphous powders at 423 K and 500 MPa. The pore ratio was about 0.6 %. The Mg amorphous alloys had higher corrosion potentials and lower corrosion current density than AZ91D alloy and pure Mg, and their corrosion resistances of Mg alloy were improved.