To provide a method for prolonging the lifetime of the ladde lining refractory for reducing damage at the initial stage of operating by enhancing strength of hot refractory.

The method for prolonging the lifetime of the ladle lining refractory comprises the steps of supplying a gas containing magnesium vapor or magnesium chloride or a gas containing steam, carbon dioxide or oxygen into a ladle 1 to fully fill the ladle 1 with the gas, and then supplying the other gas into the ladle 1. The magnesium vapor or magnesium chloride gas is reacted with steam to precipitate magnesia in ores of an alumina magnesia castable to reinforce the refractory 7 of an operating surface side, thereby prolonging the lifetime of the ladle lining refractory.