[en] The hopping conductivity of single-crystal La₂ CuO_4+δ with excess oxygen is studied.It is found that the transition from the variable-range hopping conductivity (with the temperature dependence of resistance R ∝ exp (T₀/T)^1/4 to a simple activation one (R propor to exp (Δ/kT)) occurs as the temperature is lowered below 20 K.The transition is followed by essential changes of magnetoresistance and voltage-current characteristics behavior.It is shown that such behavior of the hopping conductivity below 20 K may be attributed to the superconducting inclusions occurred in the insulating sample because of the phase separation. The observed peculiarities of the conducting properties agree well with the known effects of competition between electron localization and superconductivity in inhomogeneous systems