This study presents a benchmark evaluation of the new ENDF/B-Ⅷ.0 nuclear data library for the Organization for Economic Co-operation and Develop-ment/Nuclear Energy Agency Medium 1000 MWth sodium-cooled fast reactor (SFR). The study presented herein covers both SFR core types, i.e., metallic fueled (MET-1000) and oxide fueled (MOX-1000), simulated using the continuous-energy Monte Carlo Serpent2 code. The neutronics performances of the ENDF/B-Ⅷ.0-based simulations were compared mainly to two libraries: ENDF/B-Ⅶ.1 and JENDL-4.0. The comparison includes several neutronics parameters evaluated for the beginning and end of the cycle conditions. These parameters include the effective multiplication factor keff, total effective delayed neutron fraction βeff, sodium void reactivity (△ρNa), Dop-pler constant (△ρDoppler), and control rod worth (△ρCR). In addition, a sensitivity study was used to reveal the major isotope/reaction pairs contributing to the discrepancy observed in the performance of the three libraries using 33 and 44-energy-group structures.