An integral experiment was performed on a Be cylindrical assembly of 630mm in diameter and 456mm in thick. Measured items were reaction rates, in-system neutron spectra and gamma-ray heating rates. The experimental analysis was performed by the MCNP and DOT3.5 codes using the nuclear data of JENDL-3, JENDL-3PR1, ENDF/B-IV and LANL. For high threshold reactions and integral flux above 10MeV, the calculation based on JENDL-3 agrees well with the experiment, while the calculations of ENDF/B-IV and LANL underestimetes those compared to the experiment. For integral neutron flux of 0.16∼0.5 MeV, the calculation of JENDL-3 agrees well with the experiment. But in the case of ENDF/B-IV the underestimation is 20%. It can be concluded that the nuclear data of Be in JENDL-3 improves very much in accuracy from the temporary version JENDL-3PR1.