A semiconductor package is provided with an Aluminum alloy lead-frame without noble metal plated on the Aluminum base lead-frame. Aluminum alloy material with proper alloy composition and ratio for making an aluminum alloy lead-frame is provided. The aluminum alloy lead-frame is electroplated with a first metal electroplating layer, a second electroplating layer and a third electroplating layer in a sequence. The lead-frame electroplated with the first, second and third metal electroplating layers is then used in the fabrication process of a power semiconductor package including chip connecting, wire bonding, and plastic molding. After the molding process, the area of the lead-frame not covered by the molding compound is electroplated with a fourth metal electroplating layer that is not easy to be oxidized when exposing to air.