PURPOSE: To manufacture a high strength Al alloy having high strength by incorporating specific ratios of Cu, Ni and Mg to Al.

CONSTITUTION: An Al alloy contg., by weight, 2-10% Cu, 3-10% Ni and 1-7% Mg, contg. at need one or more kinds among 0.01-0.3% Ti, 0.001-0.1% B and 0.001-0.005% Be and the balance consisting of Al with inevitable impurities is prepd. By this method, the Al alloy for die casting having excellent strength as cast can be obtd.