A lens assembly includes a first lens, a second lens, a third lens, a fourth lens and a fifth lens are arranged in order from an object side to an image side along an optical axis. The first lens has positive refractive power and includes a convex surface facing the object side and a concave surface facing the image side. The second lens has negative refractive power. The third lens has positive refractive power and includes a convex surface facing the object side. The fourth lens has positive refractive power. The fifth lens has negative refractive power and includes a concave surface facing the image side. The lens assembly satisfies 5