An imaging lens including the first˜fifth lens arranged in sequence from an object side to an image side is provided. The first lens has at least one aspheric surface. The second lens with negative optical power has at least one aspheric surface and a convex surface facing towards the object side. The third lens with positive optical power has at least one aspheric surface and a concave surface facing towards the object side. The fourth lens with negative optical power has at least one aspheric surface and a concave surface facing towards the image side. The fifth lens with positive optical power has at least one aspheric surface and a convex surface facing towards the object side. By the above arrangement, the imaging lens has a shorter optical total length and a larger aperture for enhancing the image quality.