Abstract: Longitudinally profiled steel plate (LP steel plate) is a new type of green-saving steel product which could be widely used in industrial and civil buildings, bridges and other special structures. Its research and development have a great significance for structural optimization design and energy conservation in construction. The unusual rolling and straightening technology of LP steel plate is briefly introduced. The recent researches of Tsinghua University on material performance and component bearing capacity are comprehensively reviewed, which were studied by theoretical analysis, experimental and numerical simulation. The variation of material mechanical properties is concluded. The design methods of I-section beam with longitudinally variable thickness flanges for bearing capacity design value and deformation behavior at serviceability limit state are proposed.