It is well known that solute content has significant effects on grain refinement of Al alloys, which is mainly due to the grain growth restriction factor.In this study, we investigated the influence of solute content on the thermodynamic driving force for nucleation of binary Al alloys by CALPHAD method.Two different approaches, one calculating free energy change directly and the other based on nucleation entropy theory were used.The calculation results reveal that an increase of solute content of aluminum alloys increases the nucleation driving force, △Gv, which is valid for both eutectic-forming and peritectic-forming solute elements.