Hydrogen adsorption isotherms of crystalline C-60 were measured in the temperature interval from 223 to 573 K and under hydrogen pressure up to 2000 atm. Only the 573 K isotherm exhibited evidence for chemisorption starting from similar to800 atm. Hydrogen adsorption for isotherms measured below 473 K appeared to be not saturated even at 2000 atm. Maximum observed adsorption for these isotherms is almost the same and corresponds to 1.6-1.8 H-2 molecules per C-60. In contrast to experiments performed at lower pressure, presented data can not be explained only by adsorption of single H-2 molecule in octahedral Sites Of C-60 structure. (C) 2004 Elsevier B.V. All rights reserved.