Physical properties have long been considered to have been dependent upon the porosity and water system of soils. Recently, the soil structure seemed to be found by V. R. WIILIAMS to have an intimate relation to activities of micro-organisms and chemical changes in soils. In this paper results of experiments on secondary particles were published as follows : Secondary particles were visualized in the previous paper as its being an element of soil structure. (1) The constitution of secondary particles was independent to the content of free sesqui-oxides, but dependent on the quality of organic matters. Eh decreased in the following order, crumb, secondary particle and single particle. (2) In concerning to the water system and the permeability, the secondary particles did the function as like as the crumbs and not as the single particles. Soil water was classified into three water-systems; capillary water (available water) (PF 2.7〜4.2), swelling water (PF 4.2〜5.5) and hygroscopic water (PF 5.5〜7.0). (3) In the upland field where irrigation was made, sub-soils were, brought to be dispersed as the top-soils.