We have designed a new structure blue emission device with doped Alq 3 of 3% in hole transmission layers of NPB. The CIE coordination of the devices is (0.17,0.19). The maximum electroluminescence efficiency is 4.1 cd/A at 11V, the brightness is 118.8 cd/m 2 at 7 V, and the maximum brightness is 10770 cd/m 2 at 13 V.Electroluminescence belongs to a double molecule process, in order to obtain higher light emission efficiency, it is required that not only electrons and holes can inject, carry and compound effectively but also the injection of electrons and holes should be uniform. Thus the energy band match degree of two electrode and organic layers or between two organic layers is very important to the compound probability of the device [1][2][3][4] . To effectively improve the performance of the organic electroluminescence device, many means are adopted. For example, import a buffer layer between anode and hole; modify anode by special means; employ cathode modified materials between cathode and electron transport layer [5][6][7] ; employ doped, and so on. These methods can greatly improve the light emission efficiency of the devices. At present, the reported highest efficiency of blue light OLED is 5.0l m/ W and its surface quantum efficiency is about 2.4% [8] , however, compared with the red or green OLED, the blue OLED still has some deficiency in which luminance degree is not high enough, its efficiency is low and its life-span is short, and etc. It is well known doped that is often employed to obtain high performance device, but most of doping methods are for the radiation layer, and improve the device performance by balancing carries inject and by transferring energy between object and subject [10] . It is reported that Alq 3 is used as the buffer between anode ITO and hole transport layer to improve the performance of devices [9][10][11] . we avail of