【Abstract】 The investigations on the cell abundance, chlorophyll a concentrations and primary production were carried out in the Sanmenwan Bay during the summer of 1994The results showed that there were remarkable characteristics of the regional distribution in the Sanmenwan Bay due to the differences between the geographic environment and the hydrological conditionsThere were higher concentrations of chlorophyll a in the upper area of the bay than those in other regions of the bayChlorophyll a concentrations decreased slowly from the upper area of the bay to outside of the bay Results of the study indicate that primary production in the Sanmenwan Bay is likely regulated by the phosphate and light condition Distributive characteristics of the primary production is similarly to those of chlorophyll a The average chlorophyll a of the surface water was (318±141)μg/dm3Primary production was (2297±1139)mg/(m2·d)The average concentrations of chlorophyll a in the daytime were higher than those in the nighttime at the fixed station更多还原