Mg-4 Zn-xY alloys with different yttrium（Y） contents were prepared by high energy ball milling and vacuum hot pressing sintering. X-ray Diffraction（XRD）

optical microscope（OM） and scanning electron microscope（SEM） were used to observe and analyze the composition of the alloy and corrosion products. Through potentiodynamic polarization and immersion corrosion experiments

the corrosion properties and corrosion mechanism of the alloy were analyzed. The results indicate that with the addition of Y

the formation of new second phases(Mg

12

YZn

Mg

24

Y

5

) can be observed. After potentiodynamic polarization

passivation occurs in Mg-4 Zn-xY alloy and effective Mg（OH）

2

passivation film is generated. The addition of the Y element contributes to uniform distribution of the alloy structure and refinement of the grains

leading to the network distribution of the second phase

promoting passivation and acting as a corrosion barrier layer

and effectively improving the corrosion resistance of the alloy. Mg-4 Zn-10 Y alloy has low corrosion current density

low corrosion rate and good corrosion resistance due to its relatively uniform and fine microstructure.