The phosphorus adsorption-desorption characteristics of polyphosphate with different degree of polymerization in two different types of soil werestudied，which provided a theoretical basis for the analysis of fertilizer efficiency differences of polyphosphate fertilizer and the application of agricultural phosphorus fertilizer. Taking gray desert soil in the north and Latosol in the south as the testsoil，and conventional water-soluble phosphatefertilizer(DAP)as thecontrol，the adsorption and desorption characteristics of phosphorusin two kinds of soils with different degrees ofpolyphosphate(APP1，APP2，APP3，KTPP)were explored，and the relationship between the physical and chemical properties of different soils and the amount of phosphorus adsorption desorption was further explored. Theresults showed that in acidsoil，the phosphorus adsorption capacity of each treatment soil wasin the order ofAPP2>APP3>KTPP>APP1>DAP，and the phosphorus desorption capacity in soil wasin the order of APP1>KTPP>DAP>APP3>APP2; In gray desertsoil，the phosphorus adsorption capacity of each treatment was in the orderofAPP2>APP1>APP3>DAP>KTPP，and the phosphorus desorption capacity of soil was in theorder of KTPP>APP1>DAP>APP3>APP2. The contents of soilclay，iron and aluminum oxides in soil physical and chemical properties parameters werepositively correlated with the maximum phosphorus adsorptioncapacity(Q). SoilpH，organic m matter and calcium carbonate content were negatively correlated with Qm. To sumup，higher degree of polymerizationpolyphosphate(KTPP)has weak phosphorus adsorption capacity in gray desert soil and highsoil phosphorusavailability，while lower degree of polymerization polyphosphate(APP1)has weak phosphorus adsorption capacity in acid soil and can maintain good soil phosphorus balance and supply capacity. The higher thesoil pH，organic matter and calcium carbonatecontent，the lower the soil clay and iron aluminum oxidecontent，the lower the soil phosphorus adsorptioncapacity，thehigher the phosphorusdesorption，and the higher the soil phosphorus availability.