The effects of inclusions on microstructure, mechanical property, corrosion behavior of Mg-10Gd-3Y （GW103K） alloys by unrefining, MgO ceramic filtering and JDMJ flux refining were investigated, respectively. The results indicate that with decreasing significantly the number and size grade of inclusions for the alloy refined with JDMJ flux, tensile strength and elongation increase; however, the yield strength is less than that of the alloy refined with MgO ceramic filter and unrefined alloy. With the decrease of the inclusions contents, the corrosion rate of the alloys quickly vary from 2.419 mg/（cm 2 ·d） to 1.265 mg/（cm 2 ·d）. After inclusion content is reduced to 0.385%, the corrosion rate has almost no changes. Finally, the relationship between the volume fraction of inclusions and service properties of GW103K alloy under different conditions are established quantitatively.
