The electrochemistry and electrochemiluminescence (ECL) of copper metal cluster were studied in this work. The redox behavior observed was originated from the couples of Cu-8(+)/Cu-8(2+) Cus/Cu-8(2+), Cu-8/Cu-8(+) at the cluster metal core. ECL light emissions were observed under both annihilation and tripropylamine co-reactant conditions and only one excited state was involved in this ECL process and this excited state was also at the metal core. Theoretical investigation found that this excitation corresponds to an electron transfer from the metal core to the ligands. And the energy released from excited sate was approximate to the LUMO -> HOMO gap energy of the cluster.