investigation was carried out into the failure of super 13cr-110 tubing used in the oil industry. The depth of the gas well was 5650 m, the material of the tubing string composed of 258 3-1/2 tubing and 190 2-718 tubing was super 13Cr-110 stainless steel, while that of the casing string was carbon steel. To enhance the recovery ratio, the well was operated by fracture acidizing, while casing pressure was suddenly found rise after it was normally mined for only one year and the max imum value reached up to 80.21 MPa, at the moment, the maximum value of tubing pressure was 86.37 MPa. Therefore, the tubing string had to be removed to determine the reasons. It is noted that the gas reservoir dose not contain HzS gas The resistance of conventional 13Cr stainless steel to general and localized corrosion at higher temperature 150 C) is not good and it is susceptible to sulfide stress cracking (SSC) in wet co2 gas environment where H2S partial pressure was more than 0.0003 M Pa but the price of a superior material, 22Crduplex stainless steel, expensive 121. Therefore, super 13Cr stainless steel containing Ni and Mo in addition to Cr was developed and used widely as OCTG material in wet co2 gas environment containing small amounts of H2S in the past decade 13-5l and categorized as "13-5-2" in lso 13680 However, it is still unclear as to the application limitation of super 13cr due to the complex interaction of the environ mental-related factors l6l, such as temperature, Cl ion concentration, pH, stress, and bacteria. In addition, the on-si inspection results show that super 13cr tubing and couplings suffer from serious local corrosion in our present project. Corrosion damage of 13% cr stainless steel tubing occurring at lower temperature was also found to be severe in