We proposed a possible way of promoting the binding of H(2) molecules on covalent organic frameworks crystals via substituting the bridge C(2)O(2)B rings with different metal-participated rings, which can naturally avoid the clustering of metal atoms. First-principles calculations on both crystalline phase and molecular fragments show that the H(2) binding energy can be enhanced by a factor of four with regard to the undoped crystal, i.e. reaching about 10 kJ/mol. Grand canonical Monte Carlo simulations further confirm that such substitutional doping would improve the room temperature hydrogen storage capacity by a factor of two to three. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.