Abstract: Elaborated with reference of relevant product specification and requirements are the main aspects of R & D of the X65MS anti-H₂S ERW pipe，covering material development，pipe-making process and inspection/testing result evaluation，etc. Related test results lead to the conclusion as follows. Separately satisfactory to applicable API specification and the NACE TM 0284—2011/NACE TM 0177—2005-specified requirements are the physiochemical properties and the HIC/SSCC resistances of the X65MS ERW pipe as produced with anti-H₂S-corrosion X65MS steel coil made via well-designed low-C & Mn micro-alloying process and super-clean steel-melting technique， and by means of the ERW pipe forming process and welding process under optimized controls.