Coastalzone in the East China Sea is less than 200m depth. The Black Current flows along the land shelf. It diverges at the sea area in the west of Kyushu, and a part of the current diverged becomes a Tsushima warm current and flows in the Sea of Japan. A current in the East China Sea receives the influence of meteorological conditions, the Black Current, and fresh water from rivers, and the current presents a complex flow with fresh water inflow. There are two large rivers that bring the dissolved matter and the suspended solids such as the nourishment salts in the East China Sea, and one of the two rivers, Changjiang River, gives major effect on the above factors of water qualities. The flow of Changjiang River greatly changes from 10000m^3/s in winter to 70000m^3/s in summer. It is thought that this change in the flow influences the living thing production in the East China Sea. Also, the seasonal variation of the flowing quantity of Changjiang river decreases due to the control of the flow by the Sanxia dam, and the water quality is expected to change from the stay of the river water in the dam for a certain period. For the purpose of understanding the effect of suspended solids on the living thing production, the flow regime of river outflow water and the distribution characteristics of suspended solids will be clarified around the mouth of Changjiang River. Also, the behavior characteristics of the suspended solids will be investigated experimentally and numerically.