Abstract: An organizing device is for organizing multiple optical fiber lines to run parallel to each other on a plane. The organizing device includes a guiding unit and a positioning unit. The positioning unit includes a main body slidably disposed on the guiding unit, a first positioning part extending from the main body, and a second positioning part that extends from the main body in a same direction as the first positioning part and that is spaced apart from the first positioning part. The main body, the first positioning part and the second positioning part cooperate to define a positioning slot. The distance between the first and second positioning parts corresponds to a diameter of the optical fiber lines.