This invention provides an image capturing optical lens system in order from an object side to an image side comprising: a first lens element with positive refractive power having a convex object-side surface; a second lens element with negative refractive power; a third lens element with negative refractive power having at least one of the object-side and image-side surfaces thereof being aspheric; a fourth lens element having at least one of the object-side and image-side surfaces thereof being aspheric; a fifth lens element having a concave image-side surface, both the object-side and image-side surfaces thereof being aspheric, at least one inflection point is formed on at least one of the object-side surface and the image-side surface thereof, and the fifth lens element is made of plastic. By such arrangement, photosensitivity and total track length of the system can be reduced, and the aberration and astigmatism of the system can be effectively corrected. Moreover, high image resolution can be obtained.