Formation of biofilm on surfaces is initiated by various interactions between microbial cell surface and substratum surface. In the present study, relative importance of cell surface properties was investigated using a model biofilm community consist of 4 strains. Two of those strains (13106 & 13154) had high value of hydrophobicity (H) and two (13106 & 13156) had high value of attachment on surface (A). Biofilm formation on acrylic surfaces was conducted with batch biofilm reactor containing marine broth at room temperature for 3 days. Protein content and changes of terminal restriction fragment length pattern were investigated. Strain 13106 (high H/A) was adhered rapidly and dominant in surface during the experimental period. Strain 13156 (high H) rapidly increased during first day. Strain 13132 (low H/A) was hardly detected. The proportion in biofilm also related with production of extracellular polymeric substances (EPS). Briefly, strains with high H/A and high productivity of EPS attached rapidly than strains with low H/A and low productivity of EPS. The result implied that H is more important in adherence. [Supported by NRL for HKLee]