A method of manufacturing a terminal assembly of an alternator for vehicles and the terminal assembly manufactured by the method. The terminal assembly manufacturing method of the present invention includes a first step of notching and piercing a blank plate, a second step of deep-drawing notched portions of the plate to form a plurality of assembly protrusions, each of which has a pierced cylindrical shape protruding from the plate, a third step of trimming and piercing the plate to give it a predetermined shape, and a fourth step of coining and bending the plate, thus forming the terminal assembly.