The some model tests on pressure loads induced by granular cargo were carried out. This paper describes the properties of static and dynamic pressure distributions measured on panels of the tank model. And a simplified method to estimate the pressure loads applied by granular cargo to the bottom plates and side walls of cargo holds is proposed. The findings obtained from the present investigation are as follows : (1) The new measuring method without soil pressure gage was useful for measuring the granular cargo pressure. (2) The static component of granular cargo pressure acting on side walls and bottom plates of hold increases according to tightening of granular cargo, but the dynamic component of the pressure caused by vertical or horizontal acceleration decreases in tightened condition. (3) The formulation based on the Janssen's theory which estimates both static and dynamic granular cargo pressure distributions adequately was proposed. (4) The pressure loads estimation has been performed for the simple full-scale hold loading granular cargo, and the validity and usefulness of the proposed method have been demonstrated through the comparison with the measured value of Kuramoto's full-scale tests and the estimated value of ABS SAFEHULL method.