Corrosion behavior of 13Cr steel in oxygen-free completion fluids of the organic salt at 180 ℃ was studied. Cross-sectional morphologies of the corrosion products were observed by scanning electron microscopy. Energy dispersive spectrum (EDS) was used to study the element distribution of the corrosion product inside and outside the pits. The results show that the organic salt causes severe pitting corrosion of 13Cr steel. The width and depth of the pits increase simultaneously when the test duration prolongs, and potassium enriches inside the pits. Corrosion behavior of 13Cr steel in oxygen-free completion fluids of the organic salt at 180 ° C was studied. Cross-sectional morphologies of the corrosion products were observed by scanning electron microscopy. Energy dispersive spectrum (EDS) was used to study the element distribution of the corrosion product inside and outside the pits. The results show that the organic salt causes severe pitting corrosion of 13Cr steel. The width and depth of the pits increase simultaneously when the test duration prolongs, and potassium enriches inside the pits.