Abstract: According to zooplankton investigation data in spring and summer in Fujian sea area during 2003 to 2004, this paper analyzed and studied the species composition and quantity distribution characteristics in the area. The results showed that 226 species of zooplankton were identified with 114 species of copepods occupying 50.4%, and the great majority of species are subtropical and tropical species.The total biomass of zooplankton in summer is more than that in spring with average 90.3 mg · m^-3 and 150.8 mg · m^-3.The total biomass in spring is more in the north than in the south as Mindong fishing ground is the first, Minzhong fishing ground is second and Minnan-Taiwan bank fishing ground is the lowest, and the density area is unobvious.It is contrarily in summer, the total biomass in Minzhong and Minnan-Taiwan bank fishing ground obviously increased with boosting up by warm current, and Minnan-Taiwan bank fishing ground is highest as the density area is obvious. The dominant species are Undinula vulgaris, Temora turbinate, Acrocalanus gracilis and Eucalanus subcrassus, their density area is the main fishing ground.Compared with historical data or adjacent waters, Undinula vulgaris and Eucalanus subcrassus, are always dominant, the density area is similar.