Abstract: Corrosion behavior of strip casting B480GNQR weathering steel was studied by 72 h alternate immersion accelerated corrosion test and electrochemical test in 0.01 mol·L^-1 NaHSO₃ solution, and compared with those of B800NQ weathering steel and DOCOL700 weathering steel as well as low carbon Q345B steel. The results show that the loss of mass per unit area of strip casting B480GNQR weathering steel was 11.888 mg·cm^-2 and the corrosion rate was 43% relative to low carbon Q345B steel. Strip casting B480GNQR weathering steel among the four bare steel samples had the highest free corrosion potential, indicating that it had the best corrosion resistance; its electrochemical impedance spectroscopy was characterized by the single capacitance resistance arc with a time constant. Strip casting B480GNQR weathering steel among the four rusty steel samples had the highest free corrosion potential, indicating that it had the best corrosion resistance; its electrochemical impedance spectroscopy was characterized by a capacitance resistance arc at the high frequency end and a diffusion arc of approximate 45° segment at the middle and low frequency ends. Phosphorus content at the location of 150~200 μm away from strip casting B480GNQR weathering steel casting band surface was the highest, showing typical negative segregation of phosphorus element, which greatly promoted the corrosion resistance.