Abstract: The paper mainly involves description of the progress of R & D of P91 seamless steel tube by Pangang Group Chengdu Iron & Steel Co.,Ltd. and relevant manufacturing process characteristics. The result of the overall evaluation of the properties of the P91 tube shows that the seamless steel tube as developed has been in full compliance with relevant requirements as specified under Standard ASME SA 335 and the application criteria set by the boiler manufacturers,and met the needs of makers of supercritical(ultra-supercritical)electric generating set.