A lens and a lamp using the same are provided. The lamp includes a lampshade, a base, a lens and a light emitting diode light source. The lampshade is assembled to the base, and the lens is disposed on the base and located in the lampshade. The lens has a first surface, a second surface, a third surface and a fourth surface. The second surface surrounds the first surface to form an accommodating space conformally, and the third surface surrounds the fourth surface and is located on an outer side of the second surface. The first surface is located between the accommodating space and the fourth surface. The light emitting diode light source is disposed in the accommodating space of the lens.