To provide a foldable bicycle that is simply folded and easily carried on a floor.

A saddle frame is composed of a saddle support frame 33 into which a support axis 32 of a saddle 31 can be freely inserted, a coupling body 27 where the saddle support frame 33 is connected, and a coupling frame 36 of which one end is connected to the coupling body 27 and the other end is connected to a second support band 16 with a free rotation and movement. A rear wheel is composed of a rear wheel support frame 24 to which a rear wheel 25 can be installed, a main frame 21 connected against a rear wheel frame 24 through a crank axis 26 with a free rotation and movement, and an auxiliary frame 22 whose one side is freely inserted into a main frame 21 and another side is connected to the first support band 15 with a free rotation and movement. It becomes possible to fold a foldable bicycle 11 by lifting up a saddle support frame 33 under the condition that a support axis 32 has been pulled out from the saddle support frame 33.