An optical image capturing system includes, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. The first, the second and the third lens elements all have refractive power. The fourth lens element with refractive power has both surfaces being aspheric. The fifth lens element with refractive power has both surfaces being aspheric. The sixth lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof and both surfaces being aspheric. The seventh lens element with refractive power has an image-side surface having at least one convex shape at a peripheral region thereof, wherein both surfaces being aspheric, and at least one surface has at least one inflection point thereon.