The source, the harm, and the corrosion mechanism of hydrogen sulfide in circulat ing cooling systems in refinery plant s are analy zed.It is pointed out that the hydrogen sulf ide in water has seriously influenced the effect of water quality on corrosion inhibit ion and sterilizat ion.Even the commonly used corrosion inhibitor and g ermicide have no ef ficiency.The solut ion of these problems and the principle of choosing water stabilizer are put forward.