To provide a collision reinforcing material for a vehicle capable of maintaining the height of section and preventing deterioration of bending rigidity as much as possible even when a load is input in the collision of the vehicle.

A door impact beam of the collision reinforcing material for the vehicle is equipped with a long body part 10 having a bracket part 9 integrally formed on both ends. The body part 10 is formed in a hut shaped opened sectional shape opened at the front end par side of a web by a pair of webs 11, a central plate part 12 and a pair of side flanges 13. When the body part 10 is divided into three parts of P1, P2 and P3, the pair of webs 11 are formed so that a clearance (C1) between the front end parts of the both webs in the first part P1 is the narrowest, a clearance (C3) between the front end parts of the both webs in the third part P3 is the widest, and the clearance (C2) between the front end parts in the second part P2 between the first part and the third part becomes gradually wide as going from the first part P1 toward the third part P3.