Abstract: A folding bicycle comprises a retractable front tube set. Handles at two sides of the top of the front tube set can be folded to the same side. An eccentric rotation device is pivotally provided at the top of the front tube set to drive an internal tube to retract in an outer tube for positioning. A seat tube is pivotally connected with the front tube set. A saddle is provided at the top of the seat tube. A rear tube is pivotally connected with the seat tube. A fastening device is provided between the rear tube and the seat tube to fix the seat tube. The front tube set, the seat tube and the rear tube are connected together by a joint link, which provides the function of a joint to let the front tube set, the seat tube and the rear tube unfold or fold with one another.