Abstract: A phosphorus-copper brazing material formed of a phosphorus-copper brazing alloy which can easily be cold-worked into a thin sheet, a brazing sheet having a brazing layer of the phosphorus-copper brazing alloy, and a flow path structure for heat exchangers constructed by brazing with the alloy, are such that the phosphorus-copper brazing material includes a phosphorus-copper brazing alloy containing Cu as a major component and phosphorus of not less than about 2.0 mass % to not more than about 3.2 mass %. The brazing sheet includes a metal sheet, and a brazing material layer that is integral with the metal sheet on at least one side of the metal sheet, the brazing material layer being formed of the phosphorus-copper brazing alloy. The metal sheet may be formed of copper or a copper alloy containing Cu as a major component.