This article deals with the transformation of organic materials,and its effect on the properties of soda-saline soils.The results obtained are summarized as follows:1.Under given hydrothermal condition,the rate of transformation of organic materials in soda-saline soils as affected by microorganisms is as follows:Bacteria>Actinomycetes>Bacillus>Fungi.Azotobacter and cellulose decomposing bacteria multiplied very rapidly in the presence of added plant materials.They were beneficial to the transformation of organic materials and accumulation of nitrogen.