Abstract: An electricity-generating apparatus for bicycle includes a holder and an induction assembly. The holder is adapted to be connected to a bicycle fork. The induction assembly detachably screws to the holder. The induction assembly comprises an outer sleeve. The outer sleeve coaxially receives an insulating sleeve, an iron core and a rod. The insulating sleeve is wound by an induction coil electrically connected to the rod and the outer sleeve. At least one magnet is adapted to be engaged with the bicycle spokes for being adapted to induce a magnetic environment around the induction coil. Therefore, the induction assembly generates electricity.