An optical image capturing system comprising, 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 lens element with negative refractive power has a concave image-side surface. The second lens element, the third lens element and the fourth lens element have refractive power. The fifth lens element has refractive power. The sixth lens element with refractive power has an image-side surface being concave in a paraxial region and includes at least one convex shape in an off-axial region, wherein the surfaces thereof are aspheric. The seventh lens element with refractive power has an image-side surface being concave in a paraxial region and includes at least one convex shape in an off-axial region, wherein the surfaces thereof are aspheric.