Metal ions have very important influence on the sorption behavior of phosphate on sediments. In this research, the overlying water and sediment from Dianchi Lake were took as the sorbate and sorbent, respectively, to investigate the effect of Ca2+, Al3+ and Fe3+ on phosphate sorption on sediment. As the results showed, all these three metal ions can improve the sorption of phosphate, which in overlying water, on sediment. By contrast, the abilities of three metal ions to improve phosphate sorption on sediment were followed the order: Ca2+ < Al3+ < Fe3+. This indicated that Fe3+ is of great effect for reducing the concentration of phosphate in overlying water.