Langmuir-Blodgett (LB) films for white light emitting layer was deposited from mixtures containing as much as 0, 10, 20 and 30 mol% of arachidic acid (AA). In the Surface morphology of LB monolayers observed by AFM (atomic force microscope), phase separation, which attributed to a phase-separated polymer and organic molecule, was observed. In the voltage-current characteristics of EL device, which use mixed monolayer of 13 layers deposited by LB method as an emitting layer, Current density was much smaller than that of the spin-coated devices. It may due to the large contact resistance existed at the interface of LB layer/organic layer inhibit carrier injection to the emitting layer.