Abstract: <FONT face=Verdana>Study and analysis on morphologies and properties of phosphogypsum with different particle sizes were carried out,which will provide the theoretical basis for the exploring of high-efficient methods for the treatment of phosphogypsum.Research results showed that because of its different particle sizes,phosphogypsum had diversity of crystal morphology;with increase of the size of phosphogypsum,columnar crystals turned into flake-like crystals at first and then into cluster-like crystals;physica-and-chemical-properties of phosphogypsum would be different with the difference of crystal morphologies,and bulk density and activation index of phosphogypsum increased gradually with decreasing of its particle size;X-ray energy spectrum analysis and infrared spectroscopy showed that the hydrophobicity of phosphogypsum had a certain relationship with its content of carbon,that was,the hydrophobicity became stronger with increase of the content of carbon;and the hydrophobicity of phosphogysum was also subject to other factors,such as its surface tension when particle size of which was very small.</FONT>