Changes in the contents of aqueous and exchangeable selenium in Fluvo-aquic soil were studied by indoor simulated experiment.Calcium dihydrogen phosphate and sulphur were added to the soil.Experimental results showed that the variation of aqueous selenium content was not significant in the soil with the addition of calcium dihydrogen phosphate and sulphur.The proper addition of calcium dihydrogen phosphate increased exchangeable selenium content,but the addition of sulphur showed a weaker effect.The content of exchangeable selenium in soil increased effectively if 0.12% calcium dihydrogen phosphate was added,or 0.12% calcium dihydrogen phosphate and 0.011% sulphur were added.The results were significant of the utilization of selenium-rich soil resources and the development of selenium-rich food.