Understanding the mechanism by which environmental factors affects phytoplankton growth in summer is essential for determining polar marine ecosystem responses to global climate change.Here we deployed an online mooring system in Great Wall Bay to determine how current velocity and local physical forcing affect the temporal and spatial distribution of phytoplankton biomass in Antarctic coastal waters.The results show that chlorophyll a (Chl a)concentrations accumulated from mid-December and two significant blooms developed in January(2.74mug/ L and 3.76mug/L)and were then maintained at a relatively high level.The diurnal variations of cholorophyll aconcentrations were observed in both upper and middle layers during the monitoring period.The surface current velocity reached approximately(60-100)cm/s,while the middle and bottom current velocity was limited to about 10 cm/s.We conclude that summer winds played an important role in the surface current velocity and direction.The monitoring site appears to exchange with adjacent oceanic waters,such an intrusion of water would bring in varied phytoplankton species.The results of Pearson correlation analysis showed the significant and positive influence of low current velocity on chlorophyll aconcentrations,especially during phytoplankton blooms,whereas the increased current velocity showed the significant and negative correlations with phytoplankton biomass.