Prior to any thermodynamics studies of water clusters, one has to know all possible patterns or their hydrogen bondings. Recently, Miyake and Aida have developed directed graph model which generates all possible topological distinct hydrogen-bonded clusters. Here, a new method for generating such clusters is developed which is much faster then the method of Miyake and Aida, The results are given for all clusters with up to 12 water molecules. (c) 2005 Elsevier B.V. All rights reserved.