To provide an aluminum alloy brazing sheet which can improve erosion resistance while maintaining post-braze strength, brazability, formability, corrosion resistance and other properties even when Mg is added to the core material. The aluminum alloy brazing sheet comprises an Al—Si-based or Al—Si—Zn-based filler material cladded on at least one side of a core material. The core material comprises Si: 0.3 to 1.0% by mass, Mn: 0.6 to 2.0% by mass, Cu: 0.3 to 1.0% by mass, Mg: 0.15 to 0.5% by mass, Ti: 0.05 to 0.25% by mass, with the remainder being Al and inevitable impurities, and has the density of an Mg—Si-based, Al—Mg—Cu-based, Al—Cu—Mg—Si-based intermetallic compound with a particle size smaller than 0.5 μm of 10000/mm2 or higher, or has the density of the Mg—Si-based, Al—Mg—Cu-based and Al—Cu—Mg—Si-based intermetallic compounds with a particle size of 1.0 μm or larger lower than 5000/mm2.