The species abundance and community composition among the 6 research cruises were dynamic, indicating seasonal successions in the studied areas. During the investigation period, the 3 most abundant jellyfish species were Nausithoe punctata (relative abundance, RA:91.72%), Aglaurahe mistoma (RA: 4.20%) and Diphyes chamissonis (RA: 1.13%). N. punctata revealed marked aggregation in the study area, with a peak density of 167.04 individuals/m3 in October2008. Moreover, A.hemistoma exhibited the highest OR (52.78%), and this species alone was observed in all of the samples collected during the 6 research cruises.