FRAME STRUCTURE OF VEHICLE

A frame structure of a vehicle includes: a first member composed of a metal plate, and a second member composed of a metal plate having a thickness thinner than that of the first member, the second member integrally connected to the first member by welding. The connection portion between the first member and the second member has an inclined surface configured to obliquely connect an upper surface of the first member and an upper surface of the second member such that the upper surface of the second member is positioned to be lowered than the upper surface of the first member in a gradual manner.