In marine environment, biofilms cover most of subtidal and intertidal solid surfaces. We isolated culturable bacteria forming marine biofilms on an artificial substrate, acrylic coupons. The bacterial isolates were identified by comparison of 16S rDNA sequences. Total 115 strains were cultured and identified, 45 strains showed same sequences with other strains. Therefore, 70 strains were finally identified. The bacterial isolates belonged to a–Proteobacteria (32 isolates); g–Proteobacteria (12 isolates); CFB group bacteria (4 isolates); high GC Gram-positive bacteria (9 isolates); and low GC Gram-positive bacteria (13 isolates). The bacterial isolates may be used as standard bacteria to test new antifouling agent, and as useful bacteria to enhance settlement of commercial algae and invertebrate larvae for aquaculture.