The high-performance supercomputers will consist of several millions of CPUs in the next decade. The intercon- nection networks (INs) in such supercomputers play an im- portant role. Metacube (MC) is an attractive IN that can connect extremely large number of nodes with small num- ber of links, meanwhile it holds a short diameter and keeps the simplicity of routing algorithm. An MC( k, m) network can connect 2m2 k +k nodes with m+k links per node, where k is the dimension of the high-level cubes (classes) and m is the dimension of the low-level cubes (clusters). For ex- ample, an MC(3,3) with 6 links per node can connect 227 , or 134,217,728, nodes. In this paper, we show that the Metacube is Hamiltonian and give an efficient algorithm to construct a Hamiltonian cycle in Metacube networks.