One of the major problems facing today's oil and gas industry is stress corrosion cracking (SCC) in the external surfaces of oil and gas buried pipeline steels. In the present study the stress corrosion behavior of x-70 pipeline steel after shielded metal arc welding has been investigated. For this purpose, the alloy was welded by 90,110 and 130 welding currents. Microstructures of specimens were studied using light and electron microscopes. Stress corrosion susceptibility was evaluated using slow strain rate tests in c2 simulated soil solution in the free corrosion potential and under cathodic potential of -850 and -1200 mv with respect to Ag/AgCl (3 M KCl saturated). Scanning electron microscopy was used to examine the fracture surfaces. Different areas of weld( HAZ and WM) were evaluated using linear polarization and potentiodynamic polarization methods The results showed that by increasing the heat input, tensile strength and hardness was reduced , larger HAZ area gained and the grain size was increased. SSRT results showed that increasing the welding heat input will reduce the susceptibility to SCC. Steel samples fail at decreasing elongation with increasing cathodic potentials because the role of anodic dissolution decreases and hydrogen embrittlement mechanism will be dominant. SEM images obtained from samples confirm the brittle fracture of specimens tested in high cp potentials. It was also observed that the cracks might grow in intergranular mode. Linear polarization test showed that the susceptibility to SCC resistance is inversely related to polarization resistance. Potentiodynamic polarization test showed the lowest rate of anodic dissolution of welded samples with higher heat input. In general, results showed that the susceptibility to SCC increases by reducing heat input due to the decrease of sensitive areas.