A point-to-multipoint traffic routing method that routes a multicast traffic through a determined tree on an MPLS network. A node on an MPLS network conducting a point-to-multipoint traffic routing method receives a message with an object including topology information on a determined tree, determines whether itself is a copy node or not based on the topology information, and copies, if determined to be a copy node, the received message to transmit to at least two nodes specified as next by the topology information. The present routing method ensures smooth operations of a copy and a merge node as well as an overall network.