The new iridium complexes chelated with isoquinoline derivatives as an ancillary ligand were synthesized. The iridium complex phorsphors contained 2-phenylquinoline (pq) or 1-phenylisoquinoline (piq) as main ligands to target orange to red luminescence for the application to two- or three-conponent white organic light-emitting diodes (OLEDs). We introduced 1-(1-Naphthyl)-isoquinoline (1-NAIQ) as an ancillary ligand for new iridium complexes. The photoabroption and photoluminescent (PL) properties were investigated. The PL peaks of (pq)(2)Ir(1-NAIQ) and (piq)(2)Ir(1-NAIQ) are shown at 585 and 620nm, respectively. The ligh emitting wavelength ranges of the complexes were wide with the full widths at half maximum (FWHM) of 94 and 90nm, respectively. We estimated the HOMO/LUMO levels of these complexes from cyclic voltammetry (CV) curves and the optical band gaps by the aborption spectra. We also compared the photophysical properties of these complexes with well-known red phosphors containing acetylacetonate (acac) as an ancillary ligand.