Abstract: The two-stage homogenization process of 2055 Al-Li alloy was investigated by OM,DSC and SEM. The results show that the suitable two-stage homogenization process of 2055 Al-Li alloy is 470℃/8h 530~535℃/22~24h. The dendritic structure of as-cast alloys is obvious,the intermetallic phases in as-cast alloy consist of Cu ,Ag,Mg ,Zn,Fe and Mn enriched eutectic aluminides，Cu enriched eutectic aluminides: Al2Cu and AlCuFeMn second phase. The overburnt temperature of the alloy is 522.7℃.During the first homogenization process, firstly,Cu ,Mg and Zn enriched eutectic aluminides dissolve into matrix,then Cu enriched non-equilibrium aluminides Al2Cu gradually dissolve into matrix,except a small amount of Al-Cu-Fe-Mn phases, the size of residual phases is about 15μｍ.The second homogenization process agrees well with the results of homogenization kinetic analysis.