The data of temperature, chlorophyll a, phytoplankton and NOAA/AVHRR satellite data were analyzed about 7 stations around Wando Island area on August 30, 2005. The sea water temperature range was from 15.19℃ to 24.97℃, and there was a cold water mass from the station 1 to 5 around the outside of Chungsando Island, the water temperature was lower at the bottom than surface. The salinity was 32.41~34.03, DO was 7.40~9.14 mg/L, but the concentration of chlorophyll a was 1ug/L higher at the bottom than surface. Total phytoplankton appeared from the whole stations were 47 genus, 80 species and diatoms were dominant. A lot of dinoflagellates Ceratium furca and diatoms Thalassithrix spp. mostly appeared in the cold water mass were turned up from the station 1 to 5. 4 groups of phytoplankton clusters were shown in the surface, and 3 groups of phytoplankton clusters were shown at the bottom according to the water temperature. On the ground of the result analyzed with NOAA/AVHRR satellite data, the SST around Wando Island was 22~25℃, it was formed by thermohaline front latitudinally.