ESR spectra of radicals produced in ammonia-boron trifluoride, NH_3BF_3, and ND_3BF_3 subjected to γ-irradiated at 77 K were observed. From analyses of these spectra, the radicals were identified as a BF_3- or a NH_3BF_3- and a ・NHBF_2. The latter radical is interpreted to be prepared by a loss of a hydrogen from NH_2BF_2, which was produced by the decomposition of the NH_3BF_3. ESR parameters of the ・NHBF_2 radical were a_F=26 G, a_B=36G, a_N=260 G, and a_H=41 G, respectively. These results show that a dative bond of the NH_3BF_3 differs from that of the NH_3BH_3 in the bond strengh, although both bonds are stronger than a P-B dative bond in phoshine-boranes under γ-irradiation.