The superplasticity of fine-grained 1420 Al-Li alloy which was prepared by two-stage aging and turning rolling process was studied by constant-strain-rate tensile test. The results showed that: good superplasticity was attained at temperature range of 460°C~520°C and deformation strain rate 1×10-4s-1~5×10-3s-1. An elongation of 650% was obtained at the temperature of 650°C and strain rate of 1×10-4s-1. Furthermore, the microstructures of material before and after deformation were examined using OM and TEM. Equiaxed grains were still kept, and the second-phase particles and dislocations were observed in the deformed samples.