A comparison between the estimated chlorophyll a from OSMI, the SeaWiFS and the chlorophyll a measured from the research cruises of National Fisheries Research and Development Institute was made. The updated empirical algorithm for calibrating and validating of the estimated chlorophyll a in the East China Sea was formulated by relationship between the estimated chlorophyll a and the field one. The relationship between the chlorophyll a and the band ratio(nLw490/555) was still highest in the OSMI data after launching of KOMPSAT satellite. The distributions of OSMI chlorophyll a were compared with those of sea surface temperature, zooplankton biomass, and catch amounts of the Pacific mackerel in the East China Sea. In case of the relationships in specially winter seasons of 2002 and 2004, the zooplankton and the fish were totally depended on the distributions of SST than those of chlorophyll a.