Laboratory tests using a shaking box with 100cm length, 58cm width and 30cm height were performed to estimate amplitude of earth pressure of cohesive soil acting on fixed wall. It is shown that distributions of the amplitude of earth pressure are classified into two types according to the difference of distribution of water content or shear modulus. This distribution of the amplitude of earth pressure measured in the tests almost agrees with calculated values based on theory of elasticity. Some relation curves between distribution of shear modulus and distribution of the amplitude of earth pressure are presented.