In this study, determination of porosity for some kernel crops was aimed. In addition, relationships were investigated between porosity values and some physical properties of these kernel crops. For this aim; wheat, canola, onion seed, corn, soybean and sunflower seeds were used as vegetal material. After determination of physical properties of kernel crops, a tube system was used which was designed for porosity measurements and operates according to ideal gas law. This measurement system can be filled easily with kernel crops. Pressure of 1.3 kp cm-2 was applied to kernel crops. In tests porosity values were measured at different moisture contents related with their physical properties. In the results, relationships between porosity values, moisture contents and physical properties were found. The effect of moisture content on porosity was significant at 99% confidence level for every seed bulk.