Abstract: A group of binary Pb-Al alloys with different Al contents were designed and the effect of Al content on the mechanical properties of Pb-Al alloy was studied with adoption of metal strengthening theories. Pb-Al alloys with gradient Al content were made by vacuum induction furnace. In order to guarantee the chemical composition homogeneous of the studied alloys, rapidly quenching technique was applied for cooling the casting moulds. In the present investigation, tensile test and Charpy V-notch impact test were carried out to measure the mechanical properties. The metallographic analysis technique was used to research the relationship between the microstructure and mechanical properties. The results showed that Al in solid solution will markedly promote the tensile strength and impact energy. However, the heterogeneous precipitation with Al phase would deteriorate the mechanical properties by secondary re-crystallization phenomenon.