We have synthesized 8-hydroxy-7-propylquinoline (Zn(PQ)2) to use in OLED. Photoluminescence (PL) peak of Zn(PQ)2 was observed at 555 nm which showed yellow emission. In the cyclic voltammetry (CV) experiment, the HOMO and the LUMO of the Zn(PQ)2 measured to be 6.7 eV and 3.3 eV. So we expected that Zn(PQ)2 could be used as electron transporting layer (ETL) and hole blocking layer (HBL). In this study, we investigated the efficiency properties of OLED based on Zn(PQ)2 as ETL and HBL. Prior to film deposition, ITO substrate performed surface treatment by UV-ozone for 1 minute. Improvement of the OLED performance can be attributed to the reduction of the electron injection barrier of the Zn(PQ)2 layer.