PURPOSE: To provide a bumper reinforcing structure which possesses the excellent strength and facilitates press work and reduce weight, at a low cost.

CONSTITUTION: A bumper reinforcing structure for an automobile consists of a body 1 which is attached on a side member installation surface 4 and smoothly curved outside at the center part from both the left and right side parts, and is constituted so that the height on the sectional shape gradually increases from an inverted flat hat shape to an inverted high top hat shape, and at the center part, the step difference gradually increases from the inverted high top hat shape to an inverted two-stage hat shape, attached plate 2 which has the sectional surface shoae in a flat hat shape and is fixed on the front surface side of the body 1 and serves as the part for directly receiving the impact force due to collision, and a reinforcing plate 3 which is interposed between the body 1 and the attached plate 2 and is constituted so that the width excluding the collar part on the sectional surface shape in a hat shape is smaller than the width of the bottom part of the body 1, and the collar part is joined with bottom parts of both the left right side parts of the body 1 and the middle stage part of the center part, and the top part is joined with the top center part the attached plate 2, and is formed from a steel plate having a tensile strength at least of 600N/mm2.