Abstract: The microstructure and mechanical properties of Al-2.5Cu-2.0 Li-0.1Sc alloy in as-cast state, homogenized state and hot rolled at 480℃ with different deformation were studied by means of metallographic microscope, transmission electron microscope, hardness test and tensile test. The results show that the microstructure of as-cast Al-2.5Cu-2.0Li-0.1Sc alloy consists of coarse dendrites and a large number of non-equilibrium eutectic phases, and the segregation phenomenon is serious. After homogenizing annealing at 510℃×24 h, the dendrite structure of the alloy decreases and segregation is improved obviously. The microstructure of 62.5% rolled alloy is fibrous and no recrystallization occurs. When the rolling deformation is increased to 70.0%, dynamic recrystallization takes place, the grains are equiaxed and the microstructure is refined obviously. With the increase of rolling deformation amount, the hardness, tensile strength and yield strength of the alloy increase gradually, and the elongation increases first and then decreases. The elongation of the alloy with the rolling deformation of 70.0% is the maximum of 19.4%.