Metal-chelate materials based on polycyclic aromatic ligands are attractive for tuning emission colors of organic light-emitting diodes (OLED). In this work, quinaldic acid (QA) and 8-hydroxyquinoline (HQ) were employed as organic ligands and the corresponding zinc complexes (Zn(HQA), Zn(QA), Zn(HQ)) were synthesized. The structures of Zn(HQA), Zn(QA), and Zn(HQ) were determined by H-1-NMR, C-13-NMR, FT-IR, UV-Vis and XPS. Zinc complexes showed thermal stability up to 350 degrees C under nitrogen flow by TGA. The photoluminescence (PL) was measured from DMSO solution. The Zn(HQA) emitted a yellow light around 550 nm, while Zn(HQ) emitted a green light around 500 nm. Electroluminescence (EL) device having the structure of ITO/NPB/Zn(HQA)/Liq/Al was fabricated. The device emitted a yellow light around 550 nm. The maximum luminance of 190 cd/m(2) and current of 50mA/cm(2) were observed at 15 V in the Zn(HQA)-containing device.