High-strength pipeline steel and large diameter line pipes are often used to increase the capacity of transportation and reduce the cost associated with the construction and operation of long-distance gas pipeline projects. China’s initiatives to construct long-distance natural gas pipelines has brought in new opportunities for the development of X80 line pipes. Baosteel has designed the optimum chemical composition of X80 with high niobium and low molybdenum content. In addition,a welding experimental platform and a finite element model(FEM) have supported the development of X80 UOE pipes in an efficient and economical way. The application and recent development of X80 UOE pipes were introduced in this paper. To comply with the requirements of the Second West-East Gas Pipeline Project(2ndWEPP),X80 pipeline steel with low carbon bainite microstructure was developed by utilizing the optimized composition and TMCP process. The matching welding material,welding procedure and UOE forming processes for 1219mm outside diameter X80 UOE pipes were also developed. More than 340000 t of X80 UOE pipes were produced and applied in the 2ndWEPP. Furthermore,to meet the prospective demand for long-distance gas pipelines with an annual transportation capacity of over 40 billion m3,larger size X80UOE pipes with 1 422 mm OD × 30. 8 mm WT were trial produced recently. DWTT performance,the main technical challenge for heavier wall pipes,was improved by using optimized microstructural design. The newly developed X80 pipes can be potentially used for larger transportation capacity pipelines in China. High-strength pipeline steel and large diameter line pipes are often used to increase the capacity of transportation and reduce the cost associated with the construction and operation of long-distance gas pipeline projects. China’s initiatives to construct long-distance natural gas pipelines has brought in new opportunities for the development of X80 line pipes. Baosteel has designed the optimum chemical composition of X80 with high niobium and low molybdenum content. In an efficient and economical way. The application and recent development of X80 UOE pipes were introduced in this paper. To comply with the requirements of the Second West-East Gas Pipeline Project (2nd WPEP), X80 pipeline steel with low carbon bainite microstructure was developed by utilizing the optimized composition and TMCP process. The matching welding material, welding procedure and UOE forming p More than 340000 t of X80 UOE pipes were produced and applied in the 2nd WEPP. Furthermore, to meet the prospective demand for long-distance gas pipelines with an annual transportation capacity of over 40 billion The newly developed X80 pipes were probable to produce recently. DWTT performance, the main technical challenge for heavier wall pipes, was improved by using optimized microstructural design. used for larger transportation capacity pipelines in China.