Auther's experiments were conducted to examine sand movement on offshore zone using a glass walled wave channel showing in Fig 1. Sand having a medium diameter of the range from 2 mm to 0.125 mm, and waves from 20cm to 7cm in height and from 6 sec to 1 sec in period were used throught the experiment.
　 In this paper the follows are studied
　1. The initiation of sand movement due to wave.
　2. The direction of sand movement.
　3. The mode of sand movement.
1. THEINITIATION OF SAND MOVEMENT DUE TO WAVE. For the initiation of the general movement (due to Manohar's difinition), authers got a experimental equation as Eq(4), and compared this with the equation obtained from auther's field studies using radioactive glass sand and other's (see Fig 5).
2. THE DIRECTION OF SAND MOVEMENT. Authers indicate that the mode of sand movement is classified in the three states as shown
　a. The first-net onshore transport.
　b. The second state-net offshore transport.
　c. The third state-net onshore transport.
and show the relationship between wave charactristics and property of sand, iu thes states turning attention to the gradient of pressure amplitude at the bottom.
(see Fig.6,7,9 and Eq.(11)
3. THE MODE OF SAND MOVEMENT. Using radioactive glass sand of Cr-51, and dyed sand, authers observe the mode of sand movement of the above mentioned three states, relating it to ripple movement, In Fig, 11,13,14 typical examples of distribution of radioactive glass sand in the three states are shown.