Abstract:Eight soil samples of permeable paddy soil collected form Tai Lake Basin were investigated. The main results are summarized as follows: 1. The clay minerals of the clay fraction in the soils are predominated by hydromica, ka.olinite and montmorillonite. 2. There is distinct difference in the distributions of clay minerals between the coars clay fraction (0.002-0.001 mm) and fine clay fraction(<0.001 mm). 3. The sand fraction (1-0.05 mm) containing "iron-manganese sands" is less in SiO2 and more in Fe2O3 than the silt fraction (0.05-0.002 mm),and it is also higher in volume magnetic/susceptibility than the silt fraction. 4. Plasticity and swelling start to be found only in the clay fraction(<0.002 mm). All the properties of the permeable paddy soil mentioned above are similar to those of bleached 0paddy soils reported by the authors in 1982, but different from those of the upland soils raported by others.