[en] The yield of ¹⁶⁶Dy produced via the double neutron capture of ¹⁶⁴Dy was determined by the activation method. The γ-emission probabilities in the decay of ¹⁶⁶Dy and its daughter ¹⁶⁶Ho were measured and used for the determination of the yield. The reactor-neutron-capture cross sections of ¹⁶⁵Dy isomers were deduced from the dependence of the yield on the length of the irradiation time. Obtained cross sections were 2000 +- 600 b for the metastable state and 3530 +- 330 b for the ground state, respectively, with the choice of the Westcott epithermal index r square root (T/T₀) = 0.017. The ratio of the cross sections between the pair of isomers was discussed together with the cross section ratios of other isomer pairs on the basis of the compound formation model. (author)