A high-resolution (~ 1 mu m) three-dimensional (3D) X-ray micro-computed tomography (mu-CT) was used to nondestructively detect pore characteristics in silicon particle preforms with different starch contents (10%, 20% and 30%) and particle sizes (20, 50 and 90 mu m). A pressure infiltration equipment was made to infiltrate the preforms. The preforms were infiltrated at constant temperature (800 degrees C) and pressure (400 kPa) with different pressure-applied times (3, 5, 8, 11 and 15 s). Since the discrepancy between the infiltration heights measured in the experiment and calculated with the general infiltration equation was found, a modified infiltration equation was proposed considering the pore characteristic parameters from 3D mu-CT. The results of the modified infiltration equation showed good agreement with the experiment.