Barrier layer was prepared by Micro-arc oxidation mAO) technique in silicate solution, and cathodic plasma electrolytic deposition (CPED) technique was used to fabricate Al2O3 ceramic coatings on Ti6Al4V alloy in Al(NO3)3(30g/L) and ethanol-aqueous solutions. Surface morphology and elemental of the coatings were investigated by scanning electron microscope (SEM) and energy disperse spectroscopy (EDS). Reaction phen mena were recorded and products of reactions were analyzed by infrared absorption spectrum KBr compression method. Furthermore, mechanisms of different electrolytes were evaluated. The results show that (1)there are many open macro-pores on the surface of rough and porous coating and the bonding between coating and substrate is good, the main composition of coating is α-Al2O3 phase and the minor is γ-Al2O3 phase;(2)the content of γ-Al2O3, arc-voltage and work-voltage increase with the increase of alcoholicity and the reaction temperature of 50% ethanol-aqueous is the lowest;(3)the is hydrogen gas produced in hydrogen evolution adhere to the cathode surface, and the reducing reaction of OH- on the anode surface, and there are esters and ethers contained in reaction products of ethanol solutions.