This paper gives a brief introduction of the developmental history of high performance steel (HPS) all over the world. Emphasis of current paper is on the characteristic studies of HPS 485W, which is new structural weathered steel produced by Wuyang Steel Iron Company using quenching and tempering (Q&T) in China. To obtain the strength and ductility of HPS 485W, the tensile coupons were machined from each 8mm, 10mm, 12mm and 14mm thick plate. Based on the static tensile tests in room temperature, major of material mechanical characters were obtained, such as yield strength, ultimate strength, elastic modulus and so forth. Besides, to examine plate toughness, 30 Charpy V-Notch (CVN) specimens from 12mm thick HPS 485W plate were tested from 20 oC to -196 oC . Compared with conventional bridge steels, the CVN test results show that the fracture toughness of HPS 485W is much higher, and the brittle-ductile transition of HPS occurs at a much lower temperature. A set of 9 single-edge bend specimens were took from 20mm and 30mm thick HPS 485W separately for ductility fracture toughness test. The calculated JIC value is 415.8 kJ/m2 for 18mm thick specimen and 507.79 kJ/m2 for 28mm thick specimen, which shows ideal ductility of HPS 485W.