Vehicle body frame using component integration type rear lower

An embodiment component integration type rear lower includes a body frame having an end portion of a first side and an end portion of a second side and having a predetermined length, a front-rear connection member connecting a side sill at the end portion of the first side and connecting a rear side member at the end portion of the second side, a bush mounting member coupling a bush to the end portion of the first side, and a coupled torsion beam axle (CTBA) mounting member coupled to at least one of a CTBA, a chassis spring, or a shock absorber, the at least one of the CTBA, the chassis spring, or the shock absorber being engaged with the end portion of the second side.