Background: Shields are commonly constructed for a radionuclide neutron source in an actual calibration room in practice. Purpose: Monte Carlo(MC) calculation and experiments were applied to evaluate the effects of scattered neutrons on the neutron radiation field generated by Cf-252 neutron source with a shield. Methods: The effects of scattered neutrons caused by the shield of Cf-252 neutron source were evaluated by calculating the neutron spectra

neutron flux rate and neutron ambient dose equivalent with MC simulation. Similarly

the effects of scattered neutrons caused by the walls

ground and roof of source room were analyzed. Results: The calculation results show that the neutron flux-ambient dose equivalent conversion factor changes from 385 pSv·cm2of a bare Cf-252radionuclide from an idealized situation to 280 pSv·cm2with the shield. The contribution of scattered neutrons from the walls

ground and roof is proportional to the square of distance between wall and source. The experimental data on dose rate are consistent with the calculated results and indicate the reliability of this method. Conclusion: This study provides a practical and feasible way to calibrate the radiation protection instruments using a non-standard radionuclide neutron radiation field.