Abstract: Desorption characteristics of phosphorus from different used sandy soil in Western Liao River Basin were studied by a small backfilled earth-pillar experiment.Results indicate that the phosphorus desorption characteristics of the Western Liao River Basin sandy soil conform to the Freundlich and Langmuir desorption isotherms.D_r (phosphorus desorptive ratio) of the sandy soil was between 0.32 and 0.98,with an average of 0.70.There was a highly significant positive correlation between D_m (phosphorus maximum desorption) and Г_m (phosphorus saturated sorption).The modes of phosphorus sorption to sandy soil are based on physical sorption,which is easy to leach out of the environment,and reversible desorption is relatively strong.Therefore,there is a certain risk to the environment.Mass percentage of soil organic matter and aggregates have a great impact on fixed or maintained phosphorus capacity.The results of the phosphorus desorption experiments on different land use structures show that the order of D_r is: farmland (0.64) = grassland (0.64) ＜ forestland (0.67) ＜ sandy wasteland (0.91).The environmental risk to farmland,grassland and forestland is relatively low,whereas the environment risk to sandy wasteland is the maximum.There are highly obvious negative correlations between D_r and mass percentages of soil organic matter,clay and coarse clay.