Abstract: In present study, the neutron spectra of 241Am-Be measured with Bonner sphere method. The system was equipped with a BF3 thermal detector placed in the center of seven spheres with different diameter (from 8.89 to 30.48 cm). The energy response matrix of the system was calculated by using the Monte Carlo simulation from thermal energy to 18 MeV. The spectrometry system was calibrated, using the shadow cone technique. For this purpose, a new shadow cone was used to prevent direct neutrons of source than to account on the scattered neutrons. Regardless, having a smaller length for new cone, passing the direct neutrons for it was negligible and less than old cone (proposed in ISO). Taking into account the low energy resolution of the BSS system, shape of unfolded spectra from experiment was comparable with the standard ISO 241Am-Be spectrum.