The luminance efficiency of the blue organic light-emitting devices (OLEDs) with a mixed host emitting layer (EML) consisting of a 2-t-butyl-9,10-di-2-naphthylanthracene (TBADN) and 4,4'-Bis[ 4-(diphenylamino)styryl]biphenyl (BDAVBi)-doped 1,3-bis(carbazol-9-yl)benzene (mCP) layer at 20 mA/cm(2) was 5.78 cd/A, indicative of highly efficient OLEDs. Electroluminescence spectra for the OLEDs with a mixed host EML showed that a dominant peak at 467 nm corresponding to the BDAVBi doped mCP layer together with a shoulder at 491 nm related to the combination of the TBADN doped mCP layer and the BDAVBi doped mCP layer appeared.