A foldable bicycle includes a frame. A first foldable device is connected to a top tube of the frame so as to fold a front wheel together with a head tube and a handlebar backward at the first foldable device such that the front and rear wheels are located parallel with each other. At least one assistant wheel is connected to a lower end of a down tube so that the at least one assistant wheel cooperates with the front and rear wheels to form a stable triangle support arrangement and the foldable bicycle can be easily moved by the at least one assistant wheel cooperating with the front and rear wheels. A carry rack is located above the rear wheel, which can be positioned by engaging pivot rods of the carry rack with engaging members on two support rods connected to a hub of the front wheel.