White organic light-emitting devices based on a red fluorescent dye 3-（dicyanomethylene）-5, 5-dimethyl-1-（4-dimethylamino-styryl） cyclohexene（DCDDC） were fabricated and investigated. Two kinds of devices were processed using ultrathin technology and doping technology. The structures of the devices were as followed: 1） indium-tin oxide （ITO）/N, N′-diphenyl-N, N′-bis（1-naphthyl-pheny1）-1, 1′-biphenyl-4, 4′-diamine （NPB）/4, 4′-bis（2, 2′-diphenylvinyl）-1, 1′-diphenyl （DPVBi）/tris（8-quinolinolato） aluminum （Alq3）/DCDDC/Alq3/Mg:Ag; 2） ITO/NPB /Alq3:DCDDC/NPB/2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline （BCP）/Mg:Ag. The luminescence and efficiency characteristics of these two devices were measured and compared. The results showed that both devices A and B exhibited white light consisting of RGB three primary colors. Moreover, device A had a turn on voltage of 4 V, a maximum power efficiency of 2.4 lm/W at 5.5 V and a maximum luminance of 16690 cd/m2 at 185 V. Also, pure white emission with Commissions Internationale De L’Eclairage （CIE） coordinates near （0.330. 0.300） having a slight variation of （-0.020, +0.002） in a wide range of voltages was observed. In contrast, devices B showed a turn on voltage of 5 V, a maximum power efficiency of 1.4 lm/W at 5.5 V and a maximum luminance of 12580 cd/m2 at 17 V. The CIE coordinates had a red shift as the voltage increased and then kept near the optimum white point of （0.33, 0.33） over 9 V. It was found that the difference in characteristics of these two devices was dependent on the variation of charge recombination zone. To be specific, it was due to the direct charge trapping effect of DCDDC ultrathin layer and the properties of incomplete energy transfer in Alq3:DCDDC doping system.