The present invention provides a method of performing packet transfer among nodes on a network by a packet transfer node. When the network is divided into a plurality of network areas and routing within an individual network area and between network areas is performed, the method divides packet transfer processing of the packet transfer node into a higher layer and a lower layer, selects one of the higher layer and the lower layer for each packet to be transferred in accordance with information set in the packet transfer node, and performs the packet transfer by the selected hierarchical layer. According to the present invention, an added packet transfer node can be coupled with a network area which is not adjacent to the added packet transfer node to increase flexibility of expanding the network.