Weight is one of the most important performances for the aviation productions. The most effective approach to weight saving is developing the lower density material. Introduce advanced Al-Li (Aluminum-Lithium) alloy with lower density, higher tensile strength, better damage tolerance etc. Compare to conventional aluminum alloys and trade-off study with advanced composites. Analysis the properties of 3rd-generation Al-Li alloy and the applications on advanced aircraft. Provide the proposals of applications in civil program. The research can be the reference of materials selection and weight saving for commercial aircraft, and benefit extending applications of Al-Li alloy.