An optical image capturing system, from an object side to an image side, comprises a first, second, third, fourth, fifth, and sixth lens elements. The first lens element has refractive power, and an object-side surface of the first lens element is aspheric. The second through fifth lens elements have refractive power and both of an object-side surface and an image-side surface of the fifth lens elements are aspheric. The sixth lens with negative refractive power may have a concave object-side surface. The image-side surface and the object-side surface of the sixth lens element are aspheric and at least one of the two surfaces has inflection points. The second through fifth lens elements have refractive power. When specific conditions are satisfied, the optical image capturing system can have a large aperture value and a lower height of the optical image capturing system, and it can also improve imaging quality.