A series of novel phenanthroline derivatives (Phens) have been synthesized and their application to organic light-emitting devices (OLEDs) as an electron-transport layer was investigated. The OLEDs with a structure of ITO/alpha-NPD/Alq(3)/Phen/LiF/Al exhibited remarkable performances and lower operating voltages compared to Alq(3)-based device, indicating that Phens posses favorable electron-transport properties.