The effects of evaluated nuclear data files on neutronics characteristics of a fusion-fission hybrid reactor have been analyzed; three-dimensional calculations have been made using the MCNP4C Monte Carlo Code for ENDF/B-VII T= 300K. JEFF-3.0 T= 300K, and CENDL-2 T= 300 K evaluated nuclear data files. The nuclear parameters of a fusion-fission hybrid reactor such as tritium breeding ratio, energy multiplication factor, fissile fuel breeding and nuclear heating in a first wall, blanket and shield have been investigated for the mixture components of 90% Flibe (Li(2)BeF(4)) and 10% UF(4) for a blanket layer thickness of 50 cm. The contributions of each isotope of Flibe ((6)Li, (7)Li, (19)F, (9)Be) and UF(4) ((235)U, (238)U) to the integrated parameter values were calculated. The neutron wall load is assumed to be 10 MW/m(2). (C) 2011 Elsevier Ltd. All rights reserved.