In this paper the accuracy and reproducibility of the experiments of the equilibrium profiles of a sandy beach established by the uniform wave action of a constant steepness is discussed and is concluded to be-satisfactory. In the next place, the beaches molded from two kinds of bed materials whose median diameters are 0.2 mm and 0.88 mm, and whose initial beach slopes are 1: 10 and 1: 20, are subjected to attack by the several kinds of wave action of a constant steepness. In the equilibrium state thus attained the profiles together with their characteristics and the rate of sand transport are measured. From these experiments, the effects of the initial beach slope, wave steepness, the size of bed materials and the original beach profile upon the final equilibrium profile of a sandy beach are made clear, and some new characteristics of the movement of a shore line are found. 1. Introduction / 2. Experimental equipment and procedure / 3. Accuracy and reproducibility of experiments / 4. Equilibrium profile in the case when the grain size of bed materials and the initial beach slope are different / 5. The deformation of a sandy beach and the amount of the movement of shore line / 6. The characteristics of the equilibrium profile of a sandy beach / 7. Conclusion