Abstract: Because of its strong nonhomogeneity and large difference of spectrum between assemblies, C5G7 benchmark is usually used to test the efficiency of the computation code. When using different geometric equivalence methods for cells and an improved method for the cell homogenization, C5G7 benchmark was calculated by SN2D which was a two dimensional discrete ordinate transport code. The errors of the eigenvalue and pin power distributions were analyzed for various calculation conditions. The results show that the SN2D code can be used for the C5G7 benchmark. The calculation results can provide a direct reference to such problems as C5G7 benchmark.