Abstract:The physical properties of the major red earths widely distributed in the tropical and subtropical China were studied. The results showed that the clayey red earth containing about 60% clay particles formed under certain tropical bioclimatic condition not only had the particular chemical properties, but also possessed special physical behaviours. Their characteristics such as water retention and movement, soil rupture modulus, Broil adhesion and Atterberg's constants were quite different from the soils with clayey texture, but similar to the soils with sandy texture. One of the important reasons resulting in the physical behaviours mentioned above is attributed to the abundance of the water stable microaggregates in these soils.The unique physical properties of clayey red earths is of great significance to its rational exploitation, utilization and management.