Hydrogen induced structure transformations in amorphous alloys ZrPd, ZrRh and ZrRhBe were studied by neutron and X-ray-diffraction technique under gas pressure up to 2 kbar. It was shown that the amorphous alloy Zr(0.7)Pd(0.3) which was hydrogenated at temperature below the temperature of crystallization decomposes into metastable hyper-stoichiometric Pd-hydride with bcc lattice and amorphous hypo-stoichiometric Zr-hydride. The polyamorphous transition (transition between the amorphous phases) was reversible while the formation of metastable phase was not. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.