The removal of lead from aqueous solutions was studied using the liquid-solid extraction method. The solid used is the crude phosphocalcichydroxapatite [Ca10(PO4)6(OH)2] noted (HAPc), and the treated with a solution of lactic acid (HAPal). The extraction results showed the influence of parameters: the initial concentration of Pb(II) and the temperature of the suspensions. The application of Langmuir adsorption model showed maximum adsorption capacities of each material (HAPc and HAPal). The One specific to hydroxiapatite treated with a solution of lactic acid, was the most important (41.84mg/g). Isotherms established at different temperatures showed that this parameter affects adsorption. The best results were obtained for a temperature of 25°C compared with those recorded at 50°C. Finally, the results of this study allow us to note that the hydroxiapatite material can be a good extractant solid, for heavy metals, especially when it is modified with lactic acid. Key words: Pb(II), hydroxiapatite, chemical modification, lactic acid, adsorption. References: “K. Vijayaraghavan, J. Jegan, K. Palanivelu, M. Velan, Separation and Purification Technology.44 (2005) 53.” “C. Bleuel, D. Wesenberg, K. Sutter, J. Miersch, B. Braha, F. Bärlocher, G.J. Krauss, Science of the Total Environment. 345 (2005) 13.” “K. Kalbitz, R. Wennrich, The Science of the Total Environment. 209 (1998) 27.” “S. Saxena, S.F. D’Souza, Environment International. 32 (2006) 199”