This study aims to reduce the corrosion that occurring in mild steel (st-37). Laser has been used as inhibitor to reduce corrosion rate by using Laser shock peening (LSP) technique for st-37 submerged in hydrochloric acid with concentration of 1 M and the immersion time of 30 minutes at room temperature. The corrosion rate was evaluated by two method; weight loss method and polarization method. The results were observed that the values of corrosion rate are decreased after using the laser shock peening from 7.7210 mm/y to 1.0716 mm/y.