The adsorption characteristics of chromate and phosphate in basalt-derived soils with different ages in Hainan were investigated. The results indicated that free iron oxides and positive surface charge of the soils increased with the increase of soil age or soil development degree, thus the amount of chromate and phosphate adsorbed by soils changed in the same trends. Desorption rate of chromate adsorbed ranged from 19.8% to 39.6%, which suggested that both specific and electrostatic adsorption were involved in chromate adsorption. However phosphate was mainly adsorbed through non-electrostatic adsorption mechanisms. The amount of phosphate desorbed from soil surfaces was very low and less than 6%. The desorption of phosphate in deionized water was greater than that in 0.1 mol/L NaNO3 and KNO3. Desorption of phosphate in 0.1 mol/L KNO3 was lower than that in 0.1 mol/L NaNO3. Electrolyte affected the desorption of phosphate through the change of electric potential in adsorption plane on soil surfaces.