Impact of the construction of seawall on the backshore to nesting of loggerhead turtle Caretta caretta was investigated at the Kamouda coast in Eastern Tokushima Prefecture. Emergence number of sea turtles rapidly decreased after the construction of seawall on the backshore, where was the accumulation zone of wind blown sand and partly covered by vegetation. The reason is due to the fact that sufficient consideration of coastal environment was not taken into account in the coastal planning, because of lack of idea in the old seacoast law. Several measures to improve this situation are proposed.