Objective To research the deoxidization capacity of deoxidants acetaldoxime and sodium hexametaphosphate in softened water and the effect of sodium hexametaphosphate and acetaldoxime and pH value on the corrosion inhibiting capacity of carbon steel targeting at the quality of heating softened water. Methods The deoxidizing test, the static coupon test and the rotary coupon test were used to investigate the effects on corrosion rate of sodium hexametaphosphate and acetaldoxime, adjusting pH value with sodium hydroxide and sodium carbonate and adjusting pH=11 after deoxidization for carbon steel. Results Under the condition of doses of 160 mg/ L acetaldoxime and sodium hexametaphosphate, the deoxidization rate was 45. 68% and 71. 83% , the corrosion rate was 0. 1948 mm/ a and 0. 0728 mm/ a. The corrosion rate was 0. 0751 mm/ a and 0. 0143 mm/ a with sodium hydroxide and sodium carbonate adjusting pH to 11. And under the condition of pH=11 adjusted by doses of 120 mg/ L acetaldoxime and sodium hexametaphosphate, the corrosion rate was 0. 0885 mm/ a and 0. 0365 mm/ a, while the corrosion rate was 0. 1531 mm/ a at a dose of 140 mg / L acetaldoxime, pH = 11. Conclusion The deoxygenation rate by sodium hexametaphosphate was better than by acetal-doxime, the corrosion rate of carbon steel decreased with addition of sodium hexametaphosphate, fluctuated with addition of acetal-doxime when acetaldoxime was more than 120 mg / L, and decreased with the increasing of pH value.