Physical properties such as principal dimensions and it's related characteristics, mass of 1000 seeds, projection area, bulk and true density and porosity for three different oil producing crops (sunflower, soybean and canola) were determined at five different levels of seeds moisture content. The obtained results showed that, the principal dimensions and it's related characteristics such as geometric and arithmetic mean diameter, actual and calculated volumes, shape index (K), surface area (As), surrounded surface area (Ass), coefficient of contact surface (C.C.), the aspect ratios,  mass of 1000 seeds, seeds porosity and seeds projection area of sunflower seeds and kernels, soybean and canola seeds generally increased linearly with the increasing of seeds moisture content, on the other hand, the shape index (K), coefficient of contact surface and the aspect ratios of sunflower kernels decreased linearly with the increasing of seeds moisture content. But, sphericity of sunflower and soybean seeds and the bulk and true densities for all studied crops decreased with the increasing of seeds moisture content. Mathematical relationships were also developed for the different studied crops to relate the obtained values of all physical properties with the change in seeds moisture content.