A method of allocating an address of a network system including a central control device and a plurality of terminal devices sequentially connecting to the central control device along a predetermined wiring path, communicating with the central control device, including each of the terminal devices sequentially accessing the central control device along the wiring path, and sequentially allocating, at the central control device, the addresses to the terminal devices accessed. Accordingly, it is an aspect of embodiments of the present invention to provide a network system and a method of allocating addresses wherein addresses are automatically set and an operator can easily anticipate the set address.