In this research, we used the novel material 9-cyano-10-(2-benzothiazoly1)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro- 1H,5H,11H- benzo[l]pyrano[6,7,8-ij]quinolizin-11-one(RC545T) as a red dopant, which was synthesized from the green dopant material 10-(2-benzothiazoly1)-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro- 1H,5H,11H- benzo[l] pyrano[6,7,8-ij]quinolizin-11-one(C545T). First, we used aluminum tris(8-hydroxyquinoline)(Alq3) as a hostmaterial and doped with different concentration of RC545T, with the configuration of ITO(1300Å)/NPB(650Å)/Alq3:x%RC545T(300Å)/Alq3(300Å)/LiF(8Å)/Al(2500Å). We obtained the maximum efficiency at 2% of RC545T. Second, 5,6,11,12-Tetraphenylnaphthacene (rubrene) and RC545T as a co-dopant material were doped into the Alq3 layer. The energy transfer from Alq3 to RC545T was mainly assisted by Rubrene. Therefore, we obtained the luminance yield of 0.54 cd/A under the current density of 20mA/cm2, and the peak emission wavelength at 632nm with a CIExy color coordinate of (0.642,0.347).The improved color purity render RC545T a good red-emitting dopant in OLED application.