Abstract: Analyzed here in the paper are the causes for the fracture failure of a certain piece of tubing that has been used for three years. The following facts concerning the failure are revealed via the analysis. The failure tubing is loaded with the tensile stress along the longitudinal direction of the pipe body；so much S^2- is found in the blowout liquid as collected on the operation site；and moreover the material of the R95 tubing itself has the SSC-caused fracture sensitive characteristic. As a result，the combined effects by the above mentioned three elements leads to the SSC fracture of the tubing. On the other hand the tubing’s measured strength and hardness via the hardness test are rather high，and in general along with the increases of the strength and the hardness，the SSC fracture sensitivity of the material is getting higher and higher. Conclusively speaking，all the elements as mentioned here get the SSC fracture risk increased. Accordingly it is suggested to select as far as possible specialty tubular goods for service under acidic conditions，and to improve the quality control of the tubular goods as used under the acid conditions.