Ultrathin Y2O3-doped CeO2 (YDC) ceramic films have been prepared using Langmuir-Blodgett (LB) films as precursors. beta-diketonate complexes Ce(tmhd)(4) and Y(tmhd)(3) were chosen as the surface ions' which can combine with arachidic acid (AA) to form uniform mixed monolayer on pure water. Y-type LB films were fabricated by depositing the mixed monolayer with mixed ratio of Y(tmhd)(3)/Ce(tmhd)(4)/AA = 1:7:16. The smooth and homogeneous YDC films were obtained through a combination of room temperature ultra-violet/ozone decomposition and annealing treatments. The X-ray diffraction, X-ray photoelectron spectroscopy and a.c. impedance spectra measurements demonstrate that the final films are single YDC phase with a fluorite cubic structure indeed and the components of the films can be accurately controlled through the whole process.