An optical lens system for taking image comprises three lens elements with refractive power, from the object side to the image side: a first lens element with positive refractive power having a convex object-side surface and a convex image-side surface, and the object-side surface being aspheric; a plastic second lens element with negative refractive power having a concave object-side surface and a convex image-side surface, and the front and image-side surfaces thereof being aspheric; a plastic third lens element with positive refractive power having a convex object-side surface and a concave image-side surface, the front and image-side surfaces thereof being aspheric; wherein an aperture stop is located between the first and second lens elements. By such arrangements, it can reduce the volume and sensitivity of the optical lens system, and furthermore can obtain higher resolution.