The fixation of phosphate by pure CaCO₃ was studied. The results indicated that at lower initial phosphorus concentrations, the phosphorus was mainly adsobed on CaCO₃ concentrations, precipitations occurred, and a large amount of phosphorus could be fixed by CaCO₃. The fixation of phosphorus by calcareous soils was then studied. The results indicated that at lower range of phosphorus concentrations (0-200 μgP/ml), clay played a major role in fixing phosphorus, while at higher concentrations(>200 μgP/ml), CaCO₃ became important. Thus it is showed that calcareous soils have high fixation power of phosphorus.