In order to provide theoretical guidance for hot working and heat treatment, the equilibrium precipitated phases and the effect of elements on the thermodynamic equilibrium phases for GH720Li superalloy were studied by Thermo-Calc software. The calculated results show that there is serious segregation of Mo and Ti during the solidification of the superalloy. The quantitative rule of the contents of Al and Ti on the precipitation temperature and mass fraction of γ' phase is presented. Increment of C content leads to more precipitation of carbides, but it has no effect on their precipitation temperatures. Cr can not change the precipitation content of M23C6, but it can increase the precipitation temperature remarkably. Furthermore, the relation between the precipitated temperature of MC and initial melting point of GH720Li superalloy was studied.