In June and November 1988 samples were collected by the improved Manta neuston net at 18 stations in the soutbem Taiwan Strait. One hundred and two species and variations of phytoneuston are identified. Total individuals of phytoneuston in June are more than those in November. The horizontal distribution of phytoneuston is that the dense area occurs in the southern Taiwan Bank in June, while it appears in the western Taiwan Bank in November. The diel variations of phytoneuston are very obvions. The maximum abundance of phytoneuston occurs in the afternoon (16:00), and the minimum at midnight which is opposite to zconeuston. The relationships between phytoneuston and environment, and between phytoneuston and zooneuston are also discussed.