Abstract: The instant disclosure relates to an LED light bulb, which includes a cap, a glass bulb, an LED module, an optical element, and a power supply module. The glass bulb is disposed on one end of the cap to cooperatively define an accommodating space. The LED module, used for emitting a first light having a first bandwidth, is received inside the accommodating space. To guide the first light, the optical element is received inside the accommodating space and located at a light path of the LED module. The optical element has a light guiding portion and a wavelength transformation portion used for changing the bandwidth of the emitted light from the LED module. The light guiding portion and the wavelength transformation portion are connected seamlessly to each other. The power supply module is disposed inside the cap and electrically connected to the LED module and the cap.