An audio plug connector for mating with an audio jack connector includes a main member of cylindrical shape with a plurality of contacts exposed along an axis direction thereof. A subsidiary member is extended from a portion of an outer peripheral surface of the main member and defines at least one terminal groove at a lateral surface thereof. A front end of a bottom of the terminal groove is concaved downwards and passes through a lower portion of a front wall of the terminal groove to form a fixing groove, with a stopping portion traversing above the fixing groove. At least one conductive terminal receives in the terminal groove with a rear end thereof extended beyond a rear end of the terminal groove. A front end of the conductive terminal extends oppositely to form a buckling portion inserted into the fixing groove and restrained beneath the stopping portion.