An optical interconnection system is provided. The optical interconnection system includes an optical printed circuit board (PCB) that includes transmitter-unit and receiver-unit optical interconnection blocks for bending an optical path by a predetermined angle, an one-unit optical waveguide including an optical waveguide which is inserted into each of the optical interconnection blocks so as to connect optical paths of the transmitter-unit and receiver-unit optical interconnection blocks, and a PCB having the one-unit optical waveguide integrated therein; a light emitting element that is formed in-line with the optical waveguide on an upper surface of the transmitter-unit optical interconnection block exposed to an upper surface of the optical PCB; a driver integrated circuit that is formed on the upper surface of the optical PCB and electrically connected to the light emitting element and the optical PCB; a light receiving element that is formed in-line with the optical waveguide on an upper surface of the receiver-unit optical interconnection block exposed to the upper surface of the optical PCB; and a receiver integrated circuit that is formed on the upper surface of the optical PCB and electrically connected to the light receiving element and the optical PCB. The upper surfaces of the respective optical interconnection blocks are substantially aligned with the upper surface of the PCB