The hypercube is one of the most widely used topologies because it provides small diameter and embedding of various interconnection networks. For very large systems, however, the number of links needed with the hypercube may become prohibitively large, In this paper, we propose a hierarchical interconnection network based on hypercubes called hierarchical hypercube network (HHN) for massively parallel computers. The HHN has a smaller number of links than the comparable hypercube and in particular, when we construct networks with 2(K) nodes, the node degree of HHN with the minimum node degree is O(root K) while that of hypercube is O(K). Regardless of its smaller node degree, many parallel algorithms can be executed in HHN with the same time complexity as in the hypercube. (C) 1996 Academic Press, Inc.