Some samples of Al-Si alloy with different silicon Percentage were treated by overlapped scanning with a 2 kW CO2 laser. The structures of the Al-Si alloys after laserremelting treatment were examined by SEM and TEM.The anodic polarization curves of theAl-Si alloy samples treated by laser were measured in different corrosion solutions. Someeffects on corrosion resistance of Al-Si alloys treated by laser are discussed. Experimentalresults show that laser treatment benefits corrosion resistance of Al-Si alloy in the 10% H2SO4 and 10% HNO3 solutions; but it basically dosen't improve corrosion resistance in the 10% HCl and 5% NaCl solutions.