A new white organic light emitting diode(WOLED) was constructed by sandwiching an exciton blocking layer(EBL) between the emitting layer(EML) and the electron-injection layer.The new device with exciton confined layer shows a 50% higher efficiency and luminance than that of the device with conventional structure.It has an efficiency of 3.42 cd/A at a current density 4 mA/cm~2,a maximum luminance of 11 000 cd/m~2 at 16 V,and the CIE(Commission International de I'Eclairage) coordinates x=0.34,y=0.36,while for the device of conventional structure with the same EML thickness,the efficiency at a current density 4 mA/cm~2 is 2.15 cd/A,and its maximum luminance is 6 259 cd/m~2(16 V).The enhancement of efficiency is attributed to high density of exciton due to confinement of EBL.The dependences of efficiency on current density for both devices were examined.The slow decrease of efficiency with the increase of current density indicates weak exciton-exciton annihilation results from the florescence dye with a short lifetime.