An improved bottle holder may include a supporting board, which has a screw hole configured to connect with a screw to secure the bottle holder on the bicycle, and a lower portion of the supporting board has a supporting piece connecting with an arc-shaped elastic portion on each of both sides of the supporting piece. A limited hole and a through hole partially overlapped with each other are formed on the supporting piece, and the size of the through hole is larger than that of the limited hole, and a protruding edge is formed at a connecting portion of the limited hole and the through hole on each side thereof.