A comforter set includes a comforter piece having a peripheral edge, a comforter bag, and a fastening arrangement. The comforter bag has two cover layers overlapping to form a receiving cavity and an attachment edge. The fastening arrangement includes a plurality of first fasteners spacedly provided along an outer side of the peripheral edge of the comforter piece, and a plurality of second fasteners spacedly provided along an inner side of the attachment edge, wherein the second fasteners are detachably fastened with the first fasteners respectively to fittingly retain the comforter piece in the receiving cavity of the comforter bag at a position that the attachment edge is alignedly covered on the peripheral edge in an edge-to-edge manner to substantially pull the peripheral edge close to the attachment edge.