The multi-layered OELDs(organic electroluminescent devices) were prepared on the patterened ITO (indium tin oxide)/glass substrates by the vacuum thermal evaporation method. The $Alq_3$ (tris-(8-hydroxyquinoline)aluminum) low molecule compound was used as the light emission layer. TPD(triphenyl-diamine) and $alpha-NPD$ were used as the hole transport layer. CuPc (Copper phthalocyanine) was also used as the hole injection layers. In addition, QD2 (quinacridone2) organic material with $10AA$ thickness was deposited in the $Alq_3$ emission layer to improve the luminance efficiency. The threshold voltage was about 7V for all devices. The luminance and efficiency of devices was improved by substitution the $alpha-NPD$ for TPD as the hole as the hole transport layer. The luminance efficiency of the OELD sample with QD2 thin film in the $Alq_3$ emission layer was found to be 1.55 lm/W, which is about 8 times larger value compared to the sample without QD2 thin layer.