The electrical conductivity of Cu-Li alloys was studied. And the distribution of electrons near Fermi surface was detected by synchrotron radiation instrument. The results show that the electrical conductivity of Cu-Li alloys decreases from 5. 22 × 10-9 S/m to 3. 69 × 10-9 S/m with the increase of Li content. Li can decrease the oxygen, sulfur and other impurities content in commercial Cu, but Li dissolved in Cu lattice leads to distortion of Cu lattice from 0. 005 %-0. 050 %, affects the valence band of Cu, increases the binding energy of surface electron, and decreases the electron density of Fermi surface simultaneously. So the electrical conductivity decreases gradually with the increase of Li content.