Abstract： Objective:To investigate the main bacterial species，distribution patterns，and their relationship with human health in the nearshore seawater of the east coast of Pingtan Island.Methods:Genetic sequencing and bacterial culture methods were employed to analyze the bacterial composition of seven seawater samples collected from different locations along the east coast of Pingtan Island.Results:At the time of sampling，the air temperature of the coast in Pintan was 28.0℃，the water temperature was 24.30℃，and the dissolved oxygen concentration was 8.76 mg/L. At the dock，the water temperature was 26.60℃，and the dissolved oxygen concentration was 7.12 mg/L. A total of 29 strains of bacteria belonging to the Vibrionaceae family were isolated through seawater bacterial culture，including Vibrio alginolyticus， Vibrio parahaemolyticus，and Vibrio harveyi. Additionally，20 strains of potential pathogenic bacteria from other families，such as Escherichia coli，Enterobacter cloacae，and Enterococcus faecalis，were also identified. Genetic sequencing analysis indicated that the phylum Proteobacteria accounted for approximately 70% of the bacterial composition in the nearshore seawater of the east coast of Pingtan Island，and the genus Vibrio comprising 26.08% to 31.14% of the bacterial composition in the northeastern waters of Pingtan Island. Conclusion:The main bacterial species in the nearshore seawater of the east coast of Pingtan Island are Gram-negative bacteria，with Vibrio species being the predominant bacterial group. When treating seawater immersion injuries，antibiotics targeting Gram-negative bacteria should be given priority to consideration.