The XRD spectrum of the biomimetic coating on enamel with 1mg/L F and concentrations of rP172 amelogenin of 0, 10, 50, 70, 100 μg/mL. The presence of hydroxyapatite diffraction band (002) at 2θ=12.9, (211) at 2θ=15.9, (112) at 2θ=16.1, and (300) at 2θ=16.4 were clearly detected. The addition of rP172 didn’t alter the HAP phase significantly.