A CIS and a method of manufacturing the same, the CIS including a substrate having a first surface and second surface opposite thereto, the substrate including an APS array region including a photoelectric transformation element and a peripheral circuit region; an insulating interlayer on the first surface of the substrate and including metal wirings electrically connected to the photoelectric transformation element; a light blocking layer on the peripheral circuit region of the second surface of the substrate, exposing the APS array region, and including a plurality of metal wiring patterns spaced apart from one another to form at least one drainage path along a boundary region between the APS array region and the peripheral circuit region; a color filter layer on the second surface of the substrate covering the APS array region and the light blocking layer; and a microlens on the color filter layer on the APS array region.