A busy lamp field (BLF) system for remote telephones and a method for the same are disclosed. The busy lamp field system for remote telephones mainly has a plurality of switchboard systems and a XML server interconnected via the internet. Each switchboard system has a PBX and at least a telephone. Each telephone is connected to the XML server via internet and periodically uploads local phone status. The BLF key of each telephone is set to associate with a corresponding specific remote telephone by a subscriber of each telephone. Each telephone periodically retrieves the phone status of the corresponding remote telephone from the XML server displayed on the BLF key of the local telephone. Thus, a subscriber monitors status of a remote telephone and dials out via each PBX in addition to extension telephone of the local switchboard system.