The surface modification of commercially pure titanium (CP-Ti) by microarc oxidation (MAO) under different voltages was investigated using 1%H3PO4 solution as an electrolyte. The microstructure, phase composition and elemental distribution of ceramic coatings were investigated using scanning electron microscopy (SEM) and X-ray diffraction. The corrosion behaviour of the coating was also examined by potentio dynamic polarisation testing in a 3-5 wt-%NaCl solution. Micropore oxide films were formed on all the sample groups by MAO. The thickness and micropore size of the MAO coating increased with the increasing voltage. Energy dispersive X-ray spectroscopy results indicate that Ti, O and P became incorporated into the MAO coatings. At a low voltage of 250 V, the MAO coatings were composed of amorphous, P2O5, TiP2O7 and titania phases (rutile and anatase). Variation of treatment voltages increased the ceramic coatings from an amorphous structure to a phase structure, and the P2O5 phase disappeared. The corrosion potential Φcorr of the MAO sample shifted towards nobler directions, and the corrosion density /corr fell significantly compared with that of the bare CP-Ti. Corrosion testing showed that the sizes of the micropore of the MAO samples obviously decrease, and the MAO surface becomes smooth. [ABSTRACT FROM AUTHOR]