A photographing lens system including, in order from an object side to an image side: a first positive lens element having a convex object-side surface and a convex image-side surface; a second negative lens element, the object-side and image-side surfaces thereof being aspheric; a third lens element having a convex object-side surface and a concave image-side surface, the object-side and image-side surfaces thereof being aspheric and at least one of which being provided with at least one inflection point; and an aperture stop disposed between an imaged object and the second lens element; wherein there are three lens elements with refractive power.