Abstract: Elaborated are the property characteristics and application effectiveness of the X80 Φ1 219 mm series UOE SAWL pipes as developed by Baoshan Iron and Steel Co.,Ltd. by means of the consistent system manufacturing technology. Relevant analysis,measurements and application result demonstrate that the said X80 pipes have the advantages as extremely low C content,rather high contents of Mn and Nb,fine microstructure,high strength and toughness as well as excellent weldability,being satisfactory to the technical criteria as specified for the project of No. 2 Pipe Line under the general project of the West-East Natural Gas Transmission Project.