Disclosed herein is a method of constructing and managing an overlay multicast tree on the Internet. The overlay multicast tree includes a sender, one or more receivers and one or more agents for relaying data. At the first step, a new participant requests access to the overlay multicast tree from a tree manager while transmitting network characteristic information thereof to the tree manager. The second step is determining an optimal parent node in consideration of the network character information of the new participant having requested access at the first step and network characteristic information of agents participating in a currently constructed overlay multicast tree, and transmitting information of the determined parent node to the new participant. The new participant establishes data channels on the basis of the information of the determined parent node at the third step.