An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/Al/CuPc/NPD/Zn(salen)/Liq/LiF/Al. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/Al(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m 2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect. CLC numbers: TN383 Document code: A Article ID:Since the first report on efficient green electroluminescence from tris (8-hydroxquinoline) aluminium (Alq 3 ) in 1987 by C.W.Tang [1] , the OLEDs have become the most attractive display devices. They have high luminance, low operating voltage, ease of production, low cost, and full-color and super-thin flat panel electronic display [2] . However, because of the vibronic side band of the fluorescence spectrum and the effect of inhomogeneous broadened line, the full width at half maximum (FWHM) is usually over 80 nm for both small organic molecules and polymer OLEDs. So the efficiency of the color display made by three primary colors is very low [3][4] . To achieve the narrow-band emission of OLED, there are two main approaches. One is applying rare earth metal complexes with narrow-band property to OLED, but this method has its limitations, such as bad behaviors in luminescence brightness, efficiency and stability compared with organic electroluminescence materials of broadband emission. The other is to prepare OLED with optical microcavity structure. Optical microcavity not only achieves narrow band emission, but also achieves full-color display and tunable character [5][6][7][8][9] .Flat Fabry-Perot optical microcavity is a kind of multilayer film structure, and the main part is a distributed Bragg reflecting mirror (DBR), which is at present prepared through magnetron sputtering or electron beam evaporation. To promote the optical properties of the DBR (stop-band and high reflectivity) we need not only setting more layers but also strictly controlling layer's geometric thickness, The optical thickness of the high-and the low-refractive-index layers must reach a quarter of the chosen emission wavelength. Complicated vacuum coating equipment, rigorous arts and crafts are needed. In This paper is LiF/Al is to divide the OLED into two groups of micro-cavity luminescence units: metal-metal and metal-ITO. LiF/Al is used as an anode of upper injection unit, and can also be used as a cathode of lower injection unit. Because of the advantages of easier technics and less requirement of equipments, this structure is expected to be a new approach to improve the performance of EL.A new organic electroluminescence ...