Dissolution behaviors of Cu-20%Sc master alloy in liquid Al-0.12%Zr alloy was studied in this paper. It was found that both size and areal fraction of particles bearing Sc and Al₃Zr particles decreased,the solubility of Sc,Cu and Zr in α Al increased with increase in holding time and temperature. Part of Sc atoms was odsorbed on the surface of Al₃Zr particles so that Al₃Zr particles rich Sc on surface were formed. The microstructure of the alloy with Sc and Zr after solidification was fine observably. Average grain size of the alloy increased slightly with increase in holding time and temperature. Fine microstructure of the alloy with Zr and Sc is resulted from the a lot of stable nuclei of Al₃(Zr,Sc) particles rich Sc on surface. Same as adding Al-Sc-Zr master alloy Al₃(Sc,Zr) precipitated in the Al-Zr alloy added by Cu-Sc master alloy after homogenization.