In this paper, the factors affecting the adsorption of aqueous cadmium on Hap are investigated. Laboratory experiments show that the cadmium removal efficiencies decrease with the decrease of initial concentration of the solution, and increase with the increasing pH, reaction time (t) and Hap concentration (ρ). Orthogonal experiments indicate that the optimum conditions for the adsorption areρ=5 g/L, pH=6 andt=5 min, respectively. The experimental results demonstrate that synthetic hydroxyapatite could be used as an adsorbent for cadmium removal.