Titanium alloy with hydroxyapatite (HA) coating, which has excellent mechanical properties and biocompatibility, is a promising artificial implant. In material and biomedical science, many efforts are made to develop this composite. At elevated temperature, CaCO3 reacts with CaHPO3?2H2O to form HA. And laser-melting technique can produce ceramic coatings well bonded with substrate. So the experiment on synthesizing and cladding HA coating on TC4 surface can be made, simultaneously. 80CaCO3-20CaHPO3?2H2O with 1% Y2O3 in addition are used as raw materials. As laser treatment, the power density is 13～15 W/mm2 and the scanning rate is 630 mm/min. A graded bioceramic coating is cladded on Ti6Al4V, which mainly consists of HA. In this coating, as the depth increasing calcium content decreases, but titanium and yttrium change contrarily. The distribution of phosphorus is complex to increase followed by decrease. The porosity decreases from surface to substrate, which is similar to the distribution of micro-hardness.