Brushite (CaHPO4 2H20) was electrodeposited on titanium alloy substrate with and without H202. It was converted to hydroxyapatite [Caio(PO4)6(OH)2] by NaOH treatment. Different H202 and NH4OH doses ranging from 0 ppm to 2400 ppm and from 0 ppm to 7000 ppm, respectively were used. The results showed that with increasing H2 02 dose up to 600 ppm, the weight gain and the coating thickness are increased. Further increase of H202 dose led to decrease of the weight gain and the coating thickness. Addition of ammonia led to decrease of the weight gain and the coating thickness. Thickness and weight gain of coated brushite layer are decreased with sodium hydroxide treatment and converted totally to hydroxyapatite. Coating thickness at Ca/P ratio of 1.67 and coating time of 1 h at current density of 1.5 mA/cm2 was about 14 and 18.5 pin without and with 600 ppm H202, respectively. It decreased to about 8 pin with addition of 7000 ppm ammonia solution. (C) 2013 Elsevier B.V. All rights reserved.