Based on the two-band Ginzburg–Landau theory, we study the angular dependence of the upper critical field for the superconducting crystal Lu 2 Fe 3 Si 5. When θ=0 and θ=π/2, the theoretical results are in good agreement with the experimental data. Hence, the results support the existence of two-gap superconductivity in Lu 2 Fe 3 Si 5, previously suggested from experiments.