Abstract: LFR is one of the advanced reactor concepts which were selected for generation-Ⅳreactors. The cross section data of Pb used for LFR calculation in different databases are quite different, which could have bad impact on the accuracy of the design. Continuous cross section data of the key nuclides Pb and Bi were produced according to the latest international nuclear evaluation database JENDL 4.0, JEFF 3.2, ENDF/B-Ⅶ.0 and BROND-3.1. The effects of Pb and Bi cross sections on the effective multiplication factor were studied by using cosRMC code, the PMF035 in the international benchmarking manual and RBEC-M benchmark published by the International Atomic Energy Agency (IAEA). For the PMF035 benchmark with Pb reflective layer, the calculation deviations are less than before by using all of above nuclear databases, and the improvement of BROND is the most obvious. For the RBEC-M benchmark, the calculation results using the ENDF/B-Ⅶ.0 database are in good agreement with the results of benchmark report. The calculation results using replacement data in the other new version databases show that data of Pb and Bi from different databases can lead to different deviations in the results. The influence of Pb cross section in JENDL-4.0 on the deviation of the results is larger than that of Bi cross section.