The floating seaweeds found on the sea to the west of Kyushu were surveyed in April and June, 1959. For this purpose, thirteen survey lines were chosen in this area. Following results were obtained : 1. The floating seaweeds were found more abundantly near shore waters and coastal front of Kyushu and Goto Islands, and less in offshore area. In this district, the areas where the floating seaweeds distributed abundantly had complicated sea conditions caused from the eddies or counter currents and current rippes. Very small quantities of the floating seaweeds occurred in the main streams of Tusima Current or its branches. This is same as found in the sea to the north of Kyushu. 2. On the sea to the west of Kyushu, the floating seaweeds were found abundantly in June, compared with those of April. In this district, while the relative abundance of the species forming the floating seaweeds was much similar in April with those that found in the northern coast of Kyushu, it differed in that large proportions of weeds occupied by the species of Eusargassum in June. 3. In June, the floating seaweeds observed at the current rippes of Ariake Kai were chiefly composed of Zostera. This is the case usually met with in the bays.