A coating layer with hierarchical structure: Titanium-Zinc-Phosphate (Ti-Zn-PO4) / Hydroxyapatite (HAp) coating layer was prepared on titanium (Ti). The Ti plates were treated using two step hydrothermal treatments: first step in acidic zinc phosphate solution to form Ti-Zn-PO4 coating and second step in calcium chloride solution to form HAp. The Ti-Zn-PO4 layer strongly attached to the Ti surface. The adhesive strength of the coating layer was measured higher than 48 MPa. The surface observation and element analysis indicated that the Ti plates were covered with Ti-Zn-PO4 coating layer after hydrothermal treatment at 250°C. When Ti-Zn-PO4 coating was treated hydrothermally with calcium chloride solution, crystalline HAp layer was formed on its surface.