Single-crystalline La0.6Sr0.4MnO3+delta micro-cubes of cubic perovskite phase were prepared hydrothermally. The adopted temperature and time of hydrothermal treatment and the amount of KOH used had great effects on the low-temperature reducibility of La0.6Sr0.4MnO3+delta. The initial H-2 consumption rate of La0.6Sr0.4MnO3+delta played a vital role in determining its catalytic activity for toluene combustion. It is concluded that the perovskite-type oxide catalyst with a higher initial H-2 consumption rate displayed a higher catalytic activity for the addressed reaction.