A packet transport system to which the present invention is applied includes an edge node accommodating an access network at an edge, and a core node of carrying out a processing of assorting a frame gathered from a plurality of the edge nodes, the edge node provides a label to the frame flowing in from the access network, and the packet transport system transmits the frame in reference to the label. The edge node includes a priority information providing portion of changing a piece of priority information provided to the frame flowing in from the access network in accordance with a congested state of the core node, and a priority previously set to a path specified by the label.