Organic electroluminescent devices were prepared by vacuum evapora tion method at the condition of vacuum degrees 5×10－4 Pa,where the tradi tional material CBP and TCTA are used as host materials,respectively,and green phosphorescent dye material (Ir(ppy)₃) i s used as the guest material. The research reveals that devices with CBP as the host material are more efficient at energy transferring than that with TCTA.Subsequently,organic light -emitting devices (OLEDs) with the structure of ITO/NPB (y_1nm)/CBP:Ir (ppy)₃(x%,y nm)/TPBi (y_2nm)/LiF (0.5nm)/Al were prepared,and the influence of doping ratio of phosphorescence coloring material and the total th ickness of device on the performance is further explored.The experimental results show that,under the conditions of CBP as the host material,y=20nm,y₂=40nm and x%=8%,the device′s brightness reaches the highest, namely 67760cd/m²,when y₁=65nm,and as y_1is decreased to 40nm,the power efficiency of the d evice gets maximum,i.e.,41.2lm/W.Meanwhile,the color coordinates of OLEDs are always (0. 30,0.61) without changing.