Abstract: The investigation on the corrosion in Hu7Nan area production wells revealed that the main corrosion factor was the weak acid corrosive body formed from the production liquid containing high concentration of Cl-, CO2 (up to 4.68%) and sulfate reducing bacteria (SRB). After the efficient corrosion inhibitor KY-2 was injected into the conduit at a concentration of 100 mg·L-1, the corrosion rate was reduced from 0.0970 mm·a-1 to 0.0215 mm·a-1, the content of iron ions in the production water was reduced from 38.1 mg·L-1 to 16.5 mg·L-1,underground work for corrosion reduced 5 times as compared with that before the injection. The field tests of KY-2 in Hu7Nan area prodnction wells are all successful.