In this paper, radiographs of soil macropores were obtained by using soft X-ray radiography and several quantitative analysis were carried out by image processings. The soil samples tested were andosols which have a lot of macropores and duralumin samplers were used due to their strong X-ray transmittance property. The methodologies and experimental results are as follows : 1) By injecting liquid contrast agent (CH2I2) into the soil samples, the fluidities were recorded using a X-ray TV video camera. It can be seen by the video recording that the fluid flowed with pulsatory motions in the macropores connected with each other. 2) The spatial structures of macropores (in 3D graphics) were drawn from the stereoradiographs using a personal computer resulting to the visual observation on the spatial continuities of soil pore structures and the calculation of their actual lengths. 3) The coefficient of the permeabilities were calculated by using the fluid velocities and the diameters of the main macropores, respectively, and compared with the values of the permeability tests. Differences were found among the permeability values of the main macropores and of the soils. The results of this experiment show the importance of a more reliable information on soil macropore structures through the improvement of the experimental procedure.
