A manufacturing method of an antenna structure includes the following steps: producing a main body by injection molding of a first plastic, wherein the first plastic is a plating grade plastic; covering the main body by a second plastic to form a covering layer, wherein plating can not be done for the first and second plastics concurrently; removing a pre-determined portion of the covering layer, wherein a patterned layer is defined by the unremoved portion of the covering layer, wherein at least one trench is formed by the exposed portion of the main body and surrounding patterned layer; and plating an antenna material in the trench to form an antenna. Thus, the instant disclosure can reduce the manufacturing cost of the antenna structure. Based on the preceding manufacturing method, an antenna structure is also disclosed.