An aluminum alloy brazing sheet having high corrosion resistance is provided, which develops the sacrificial anticorrosion effect in both surfaces of the sheet, which has the brazing function in one of both the surfaces, and which prevents the occurrence of preferential corrosion. A channel forming component for a vehicular heat exchanger is also provided by utilizing the aluminum alloy brazing sheet. An aluminum alloy brazing sheet having high corrosion resistance includes an aluminum alloy core, a filler material clad on one surface of the core, and a sacrificial anode material clad on the other surface of the core, wherein the filler material, the sacrificial anode material, and the core have respective predetermined alloy compositions. A channel forming component for a vehicular heat exchanger is manufactured using the aluminum alloy brazing sheet having high corrosion resistance.