A motorcycle comprising: paired left and right rear frames (23L, 23R); a storage box supported by the paired left and right rear frames (23L, 23R) and storing articles; a seat provided above the storage box and on which any of a rider and a passenger sits; and a rear side body cover (50L, 50R) covering sides of the vehicle body below the seat, characterised in that: said storage box includes a first storage portion provided between said paired left and right rear frames (23L, 23R), and a second storage portion provided so as to bulge toward the outside of said rear frame (23L, 23R) in the vehicle width direction from the first storage portion, and communicating into said first storage portion; said first storage portion and an upper face of said second storage portion are formed of a first member; a side face and a bottom face of said second storage portion are formed of a second member; the second member includes a hanging portion hanging outside said rear frame (23L, 23R); and said first member and said second member are vertically engaged with each other in the height direction. paired left and right rear frames (23L, 23R); a storage box supported by the paired left and right rear frames (23L, 23R) and storing articles; a seat provided above the storage box and on which any of a rider and a passenger sits; and a rear side body cover (50L, 50R) covering sides of the vehicle body below the seat, characterised in that: said storage box includes a first storage portion provided between said paired left and right rear frames (23L, 23R), and a second storage portion provided so as to bulge toward the outside of said rear frame (23L, 23R) in the vehicle width direction from the first storage portion, and communicating into said first storage portion; said first storage portion and an upper face of said second storage portion are formed of a first member; a side face and a bottom face of said second storage portion are formed of a second member; the second member includes a hanging portion hanging outside said rear frame (23L, 23R); and said first member and said second member are vertically engaged with each other in the height direction. said storage box includes a first storage portion provided between said paired left and right rear frames (23L, 23R), and a second storage portion provided so as to bulge toward the outside of said rear frame (23L, 23R) in the vehicle width direction from the first storage portion, and communicating into said first storage portion; a first storage portion provided between said paired left and right rear frames (23L, 23R), and a second storage portion provided so as to bulge toward the outside of said rear frame (23L, 23R) in the vehicle width direction from the first storage portion, and communicating into said first storage portion; said first storage portion and an upper face of said second storage portion are formed of a first member; a side face and a bottom face of said second storage portion are formed of a second member; the second member includes a hanging portion hanging outside said rear frame (23L, 23R); and said first member and said second member are vertically engaged with each other in the height direction.