The purpose of this research is to learn more about the phytoplankton community structure in Maluku's Seram Sea, Manipa Strait, and North Banda Sea. A phytoplankton net (Kitahara net) was used to collect samples at depths of 150-250 meters and 0-150 meters. The sampling was done only once. The phytoplankton samples were placed in a plastic container, tagged, and preserved with a 4% formalin solution. Samples were collected from the waters of the Seram Sea, Manipa Strait, and north of the Banda Sea from 1 (one) research site each. Each study station was sampled only once. A phytoplankton net (Kitahara net) was used to gather phytoplankton. The phytoplankton net is collected by lowering it from the boat until it reaches the appropriate depth, then pulling it vertically up to the surface at a speed of 0.5 m/s. The 87 species found in the three waters are divided into 16 families for the Diatomophyceae class, 8 families for the Dinophyceae class, 5 families for the Prymnesiophyceae class, 1 family for the Prasinophyceae class, and 1 family for the Chlorophyceae class. Ceratium (Tripoceratium) sp., Rhizosolenis sp., Chaetoceros spp., planktoniella sol, Centrodinium sp., Amphisolenia sp., Protopperidinium sp., Climaodcium frauenfeldianium, and coscinodiscus stellaris are common phytoplankton species.