Abstract: Taking the Φ508 mm×75 mm steel pipe as an example, the development of the P91 hi-temperature, hi-pressure boiler pipe by Jiangsu Chengde Steel Pipe Co., Ltd.is described, focusing on the manufacturing process and the mechanical test results of the pipe.A series of test researches and relevant customer evaluations show that the manufacturing process for the said P91 hi-temperature, hi-pressure boiler pipe is practical, the mechanical properties under both ambient temperature and hi-temperature are in compliance with relevant requirements as specified in Standards ASME SA335 and GB5310-1995.With the least square method, the creep rupture strength of the pipe with a duration of 100, 000 hours and at the temperature of 600 ℃ is deduced as 89.2 MPa which is up to the operation requirement by the supercritical generation set of the thermal power plant and can be substituted for the imported similar pipes.