The transverse electrical resistance of HoBa2Cu3O7−δ single crystals is investigated in the temperature range Tc − 300 K for optimally-doped (Tc ≈ 91 K) and oxygen-poor
(Tc ≈ 51 K) samples. With decreasing temperature, the resistivity of the optimallydoped samples has been found to transit from the regime of scattering on phonons
and defects to the regime of “semiconductor” character and, near Tc, of the fluctuation conductivity. The oxygen-poor samples have been revealed to exhibit only a variable
range hopping conductivity of “semiconductor” character, which near Tc transits into the fluctuation conductivity. A significant anisotropy of the residual resistivity and characteristics of the fluctuation conductivity is observed for samples of both types.