A fiber structure that includes a liner, and a fiber reinforcement base material formed of a fabric. The fiber reinforcement base material externally covers a body portion and a dome-shaped portion of the liner, and includes first yarns and second yarns. The first yarns are arranged such that a direction in which a yarn main axis of each of the first yarns in the body portion and the dome-shaped portion proceeds is a circumferential direction of the liner. The second yarns are arranged such that a direction in which a yarn main axis of each of the second yarns in the body portion proceeds is an axial direction of the body portion and that a direction in which a yarn main axis of a portion of each of the second yarns arranged in the dome-shaped portion proceeds is an axial direction of the dome-shaped portion.