In this research, the Cr/TiO 2 composite coatings were formed in Na 2 HPO 4 + NaOH + Cr 2 O 3 by micro-arc oxidation (MAO) technology with different ratios of anodic and cathodic currents. Surface morphology results showed that the pancake-like structures on the coating surface decreased with the ratio decreased. XRD results showed the TiO 2 :Cr 3+ coatings are composed of anatase and rutile phase and the anatase content first increased and then decreased. XPS results indicated that Ti2p spin-orbit components of the Cr/TiO 2 composite coatings are shifted towards higher binding energy, compared with the pure TiO 2 coating, suggesting that some of the Cr 3+ ions are incorporated into TiO 2 lattice. The photocatalytic experiment results showed that the photocatalytic activity of Cr/TiO 2 MAO coatings can be greatly enhanced with a moderate amount of Cr 3+ .