Abstract: A cover of a wiring box for use in a telecommunication line is disclosed. At least two connection ports are formed on the cover for wiring various telecommunication lines such as indoor and outdoor telecommunication cables with various sources. If the extension line is poor or the telephone exchange line is failed some day, the maintenance worker just needs to perform the repair process on the connection ports directly. There is no need to detach the cover. Accordingly, the multiple functions of facilitating the repair process and reducing the required repair time are achieved.