The floating seaweeds marked with post cards were liberated on the sea to the north of Kyushu six times between April and August, 1959 and five times between May and July, 1960. Drifting course of the floating seaweeds was concluded from the recovery station of the post cards. There seems to be little difference in drifting movement between the marked floating seaweeds and the drift bottles released at the same time. It is concluded that almost all of the marked floating seaweeds drift to the eastward. But the destination whether they cast up on the beach of Fukuoka and Yamaguti Prefectures or go further into Japan Sea is affected by the direction and force of the wind. Average speed of the marked floating seaweeds drifted faster falls into the range between 6~11 miles per day.