The corrosion performances of the as-cast and solution-treated Mg-0.5Zn samples were investigated in 0.9％NaCl solution and compared.From the electrochemical measurement results and corrosion morphol-ogy observations,it is found that the corrosion resistance of Mg-0.5Zn deteriorated with the extension of solution treatment duration.The main reason was the formation of Fe-Si precipitates with higher Fe concentrations during heat treatment.The Fe-Si precipitates,especially the ones with high Fe contents influenced the corrosion initiation and propagation significantly.In regard of corrosion performance,the solution-treated and then extruded sample was also performing not as good as the cast and then directly extruded sample.