Abstract: In the fast reactor analysis, one of the most important things is generation of homogenized cross sections starting from the evaluated nuclear data files. By using point-wise cross section directly during the generation of problem dependent ultrafine group cross section, the treatments of the elastic scattering resonance effect of intermediate atom weight nuclide and the interference effect of all nuclides would be more accurate. Therefore, the neutron spectrum obtained from solving neutron transport equation could be more accurate and it would be the weight function for group condensation. Comparing with Monte Carlo continuous energy calculation, the results obtained by using point-wise cross section directly show that the relative differences of ultrafine group cross sections and few group cross sections after group condensation are both less that 1%. Consequently, the core analysis could get better results.