PURPOSE: To obtain the high strength Al alloy having an excellent elastic modulus and low thermal expansibility by adding specified refractory metallic elements to an Al-Mg-Li series alloy or an Al-Mg-Li-Cu series alloy having specified compsn.

CONSTITUTION: To an Al alloy contg., by weight, 1.5 to 6.0% Mg and 1.0 to 3.0% Li or furthermore with 0.01 to 3.0% Cu, one or ≥2 kinds among 0.2 to 1.0% Ag, 0.01 to 30% Ni, 0.01 to 5.0% Fe, 0.01 to 20% Ti, 0.01 to 5.0% V, 0.01 to 5.0% Mn, 0.01 to 5.0% Cr, 0.01 to 5.0% Zr and 0.01 to 30% Si are added as refractory metallic elements forming intermetallic compounds and distributing to the improvement of the elastic modulus of the alloy and to the reduction of its thermal expansion coefficient, and alloying is executed. The Al alloy having high strength, a high elastic modulus and a low thermal expansion coefficient as automobile parts such as connecting rods and pistons can be obtd.