In order to extend the scope of application of BaF2 scintillators in the diagnosis of the fast-pulse-radiation-field, an ultraviolet-light-filter has been dev eloped for the modification of the scintillation spectrum. The experimental resu lts reveal that the filter, which is composed of Al2O3, Mg F2, and Al, has a very low transmittance to the slow component light emitted by BaF2 in the in cident angles from 0°to 45° with respect to the surface normal, but has a rela tively high transmittance to the fast component light also emitted by it. The pr operty of the temporal response curve has been obtained by use of a pulse x-rays source, and the damage effect induced by the irradiation of the neutron with an energy of 14.1 MeV is also introduced in this paper.