The theory development of structural vacancies formation in palladium hydride on the molecular-kinetic presentations is the subject of this paper. The production of vacant-ordered superstructure of Cu3Au type has been considered at the high temperatures. The calculation of free energies of the PdH and Pd3VH phases has been carried out. The constitution diagram defined the temperature and concentration regions of phases formation with the Al and L1(2) structures and regions of two Al + L1(2) phases realization has been constructed. The results of theoretical calculations are in agreement with experimental data. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.