[en] Thermal stability and primary phase of Al_85+xNi_9-xLa₆ (x = 0-6) and Al₈₅Ni_9-xCu_xLa₆ (x = 0-9) amorphous alloys were investigated by X-ray diffraction and differential scanning calorimeter. It is revealed that replacing Ni in the Al₈₅Ni₉La₆ alloy by Cu decreases the thermal stability and makes the primary phase change from intermetallic compounds to single fcc-Al as the Cu content reaches and exceeds 4 at.%. When the Ni and La contents are fixed, replacing Al by Cu increases the thermal stability but also promotes the precipitation of single fcc-Al as the primary phase