Abstract: A new technology has been developed for high strength bridge wires: steel wires are coated with aluminium (Al) and zinc (Zn) alloy. It is expected that the bridge wires coated with Al-Zn have better corrosion resistance than the Zn coated ones. The steel wire with a diameter of 5 mm coated with Al (10%) and Zn alloy is produced and corrosion acceleration tests have been conducted. The steel wires are kept under three different corrosion environments: kept at a relative humidity (RH) of 60%, at a RH of 100%, and wrapped with wet gauze (wet condition). The wire specimens are kept in the thermo-hygrostat at 40°C for five months. The mass loss due to corrosion under RH = 60% and 100% is much smaller than that wet condition. The mass loss of the Al-Zn coated wires under the wet condition shows much smaller than that of Zn coated wires.