In this paper, we propose a new universal network, called recursive dual-net (RDN), as a potential candidate for the interconnection network of supercomputers with very large scale. The recursive dual-net is based on a recursive dualconstruction of a base network. A k-level dual-construction for k > 0 creates a network containing (2m)2k /2 nodes with node-degree d + k, where m and d are the number of nodes and the node-degree, respectively, of the base network. The recursive dual-net is node and edge symmetric and can contain huge number of nodes with small nodedegree and short diameter. For example, we can construct a symmetric RDN connecting more than 3-million nodes with only 6 links per node and a diameter of 22. We investigate the topological properties of the recursive dualnet and compare it to that of other networks including 3D torus, WK-recursive network, hypercube, cube-connectedcycle, and dual-cube. We also establish the basic routing and broadcasting algorithms for the ...