In order to study the microstructure evolution of Al2O3 ceramics coatings during cathodic plasma electrolytic deposition (CPED) process, Al2O3 coatings were fabricated via CPED technique on prepared TiAl alloy in Al(NO3)3 electrolyte with different time. Microstructure, morphology and chemical compositions of coatings were analyzed by scanning electron microscopy (SEM) with energy–dispersive spectroscopy (EDS), transmission electron microscopy (TEM) and X–ray diffraction (XRD), and heat–resistance of TiAl alloy substrate and CPED coating were tested. The results indicated that the growth process was divided into three stages, the initial stage, the medium stage and the late stage. The barrier layer was broken down and the coating grew slower in the initial stage, and with uniform and good combination with the substrate. The CPED coating grew stable and more rapid in the medium stage, and the crystallinity of the CPED coating was improved. In the late stage, contained 87.5 % α–Al2O3, the main phase and 12.5 % γ–Al2O3, the CPED coating grew slower, and the loose and porous outer coating was fabricated.