An LED unit includes an LED and a lens receiving the LED. The lens includes a first light-incident face confronting the LED to refract the light emitted from the LED with a small angle into the lens, a second light-incident face surrounding the LED to refract the light emitted from the LED with a large angle into the lens, a light-reflecting face to reflect the light from the second light-incident face towards a top of the LED, a first light-emergent face to refract the light from the first light-incident face out of the lens, and a second light-emergent face to refract the light from the light-reflecting face out of the lens.