PURPOSE: To provide structure of an installation part of a rear suspension capable of securing an allowable expansion stroke of a shock absorber and a suspension springwithout greatly overhanging a suspension tower to the indoor side to a certain degree and preventing falling of a side structure due to a push-up load of a suspension.

CONSTITUTION: A side frame 3 jointed and fastened on both side edge lower parts of a floor panel 1, a frame lean hose 4 to partition a closed section of the side frame 3 vertically in the car length direction, a cross member 5 provided between both of the side frames 3 jointed and fastened on the lower surface of the floor panel 1 and one end is jointed to the side frame 3. Additionally, it is constituted of a cross member lean hose 6 the other end of which is jointed to the cross member 5, a wheel apron 2 jointed to the floor panel 1 and a rear apron lean hose 15 an upper end of which is jointed to an upper end of the wheel apron 2 and a lower end of which is jointed to a car body outward side of the side frames 3.