PURPOSE: To improve drastically bend and fatigue resistance, by a method wherein a core thread is provided within a hollow part of a braided round rope having the hollow part braided cylindrically of an even number of yarn stripes of at least 4 pieces in a reinforcement body.

CONSTITUTION: A reinforcement body 2 is constituted of a plurality of round braided ropes 7, 7,... having hollow part 8 braided cylindrically of an uneven number of yarn stripes 6, 6,... of at least 4 pieces and a core yarn 9 inserted and arranged within the hollow part 8 of the round braided ropes 7 each. An inorganic fiber, organic fiber and metallic fiber are used as a kind of the yarn stripe. Furthermore, either spun yarn comprised of a long fiber and short fiber or mixed yarn of them may be good, the same may be selected appropriately in accordance with requiring properties of a cogged belt A in short. If a braided number of the yarn stripes 6 constituting the round braided rope 7 are of an even number of pieces of at least 4 pieces, they are good whichever number they may be. A reason why the braided number of the yarn stripes are made into the uneven number of pieces of at least 4 pieces is that it is necessary to form the cylindrical hollow part 8 within the braided rope.