The present invention relates to a method of efficiently assigning addresses in a WPAN and a WPAN device. The address assignment method of the present invention is performed by a higher device. Address assignment information for determining an address to be assigned to a lower device, is managed. An address is assigned to a lower device that requests connection from the higher device based on the address assignment information. The address assignment information is updated to a address value as the address value is assigned, and the updated address assignment information is transmitted to lower devices. If an update of address assignment information is requested by the lower device that assigned an address value to a device lower thereto, the address assignment information is updated and the updated address assignment information is transmitted to lower devices.