This invention relates to a fly reel, of which the drag system installed in the frame thereof comprises: a drag knob that is connected rotational to one side of periphery of the center shaft that is connected fixed to hub of frame; a drag disk that is spaced-apart from said drag knob and gets inserted rotational to periphery of said center shaft; a braking means for restraining said drag disk from rotating on said center shaft in accordance with transferred amount of said drag knob moved to axial direction of said center shaft; a drag disk bush that is inserted at said drag disk for being rotated together with said drag disk as said drag disk rotates, the drag disk bush having said center shaft inserted therein; a oneway bearing that is inserted at periphery of said drag disk bush, for permitting one directional rotation but for restraining the other directional rotation; and a drag cover that is inserted rotational at periphery of said center shaft so as to be rotated by regulated rotation of said spool, for enabling said oneway bearing to rotate together as said spool rotates, thereby overall configuration can be made efficient and simple; and set direction of oneway bearing can be converted easily if necessary.