PURPOSE: To provide a method for adding a rare earth metal in the form of an oxide to a molten metal bath.

CONSTITUTION: The light metal-rare earth metal alloy can be produced by adding pellets composed essentially of a mixture of a light metal powder and a rare-earth-metal-containing compound to a molten light metal bath. Moreover, (a) a mixture of powdered aluminum and scandium oxide powder is prepared so that the amount of the aluminum is higher than that of the scandium oxide, (b) the mixture is compressed into pellets under high pressure at a temp. not higher than about 600°C (1112°F), (c) the pellets are provided with wettability to molten aluminum, (d) the pellets are added to the molten aluminum bath, and (e) aluminum oxide is removed from the above bath, by which an aluminum- scandium master alloy can be produced.