The object of this work was an investigation of the relationship between soil moisture content and soil aeration in the structureless soils, and a theoretical consideration was proposed out:For a given moilture content，the water which enters the soil must not displace,the volume of air equal to that of the water which penetrates the soil, and the decrement of permeability of soil to air will not be found to bear a linear relation to the increment of the water content, however, the permeability also probably increases as the soil is wetted. All of this has been proved by the experiment. Furthermore, the results of the experiment showed that until the moisture content of the soil increased up to the level 33-45% the antipode of the moisture content and soil aeration in structureless soils then would be ture. It has been suggested that this could happen in the so-called ideal structureless soils (soil without non-capillary pore space) only. Under natural conditions, however, in author's opinion, the antipode of soil moisture content and soil aeration in structureless soils will not be so seriously as we generally had thought of.