Abstract: The effect of new neutralizing corrosion inhibitors, SF-121B and BZH-1, for inhibiting carbon steel corrosion in H_2S-HCl-H_2O system on the top of atmospheric and vacuum distillation tower was studied. The result indicated that with the H_2S concentration increasing, the corrosion rate increased. With the temperature increasing, the pH value of solution decreased and the corrosion rate increased. Neutralizing corrosion inhibitors, SF-121B and BZH-1, which had more excellent inhibited corrosion than the corrosion inhibitor 7019. The mixture of SF-121B and ammonia not only had excellent inhibited corrosion but also reduced operation cost.