During Jul-18 to Aug-7 2006,influence of the typhoon Kaemi (landed on Jul-25) on the photosynthetic carbon fixation of surface phytoplankton assemblage in a coastal area (Nanao,23° 24’ N,117° 07’ E) of the South China Sea was investigated with special reference to the impact of solar UV radiation.Chlorophyll a concentration was reduced from 12 μg L -1 to 1.6 μg L -1 immediately after the typhoon,which increased gradually to 7.9 μg L -1 in a week.