The valence electron structures of Al3Er and Al3(ZrxEr1-x) phases resulted from minor elements Er and Zr addition to Al alloys were calculated according to the empirical electron theory in solid and molecule (EET). Effects of Zr contents on the valence electron structure parameters of Al3(ZrxEr1-x) phases were discussed. The calculation results show that with the increase of Zr atom content, both the covalent electron pairs nα on the strongest bond for strength properties characterization and the phase structure forming factor S decrease, which indicates Al3Er phases firstly precipitate during the solidification process and Al3Zr and Al3(ZrxEr1-x) also precipitate during the subsequent heat treatment; whereas, Zr addition has few influence on the strength of the alloys. The density of crystal lattice electron ρ for plastic properties characterization increases first and then decreases, revealing that Zr addition can obviously improve the plastic properties of the alloys.