A method of manufacturing an LED light string using a jig having a main body and a plurality of spiral grooves formed thereon adjacent to each other is provided. The method includes winding an electrical wire in each of the grooves, removing portions of the electrical wires to provide a plurality of spaced exposed segments at successive locations on each of the electrical wires, placing LED chips on at least some of the plurality of exposed segments formed in one of the electrical wires, connecting each LED chip to a corresponding exposed segment on a different electrical wire by a connector, and sealing each LED chip and connector. A jig for attaching one or more LED chips to a plurality of electrical wires is also provided.