Gradient hydroxyapatite (HA) coatings are prepared on Ti6Al4V substrates and consist of different proportions of HA and yttria-stabilized zirconia (YSZ). Their surface morphology, cross-sectional structure and phase composition are investigated. The surface morphology is coarse and uneven with well-distributed concaves. The coatings become crystalline after post-treatment in water vapor. The structure of the atomic (Ti, Ca, P, Zr etc) intermixed zone in the interfacial field indicates that there is a diffusion layer (∼3–5.0 µm) between the coating and the substrate. The coating is found to be bioactive and nontoxic. The coating has a much-higher binding strength than monolithic-HA coatings.