Some physical and aerodynamic properties of soybean were determined in order to design processing equipment and facilities. In this study, some physical properties of soybean were evaluated as a function of moisture content in the range of 6.7-15.3% (db). At the 6.7% (db) moisture content the average length, width, thickness, unit mass, the geometric mean diameter, arithmetic mean diameter, sphericity, porosity, true and bulk density soybean were 7.41 mm, 5.34 mm, 4.50 mm, 121.76g, 5.62 mm, 5.75 mm, 75.0, 51.0,1062.6 and 804.8 kg m-3, respectively. Corresponding values at 15.3% (db) moisture content were 9.57 mm, 6.75 mm, 5.17 mm, 223.65 g, 5.62 mm, 5.75 mm, 72.0%, 44.2%, 1086.4 and 689.3 kg m-3 respectively. In soybean, terminal velocity increased from 7.13 to 9.24 m sμ-1 and the coefficient of static friction increased linearly against all the tested surfaces as the moisture content increased. © 2006 Asian Network for Scientific Information.