Comparision of the classical taxonomy and the numerical taxonomy was carried out on 108 strains isolated from Chung-mu bay and it was confirmed that correlation coefficient measured between strains represented similarities. Gram stain is the most important test in the classical taxonomy, while Gram positive and Gram negative strains were distributed evenly over the whole cluster and coccus and rod were separated in the numerical taxonomy. Both the numerical taxonomy and the classical taxonomy showed high similarity in the classification between the genera. The strains collected in bottom layer marked lower taxonomic similarity between strains than those in upper and middle strains. The distance between the inside (Group I) and the outside (Group II) strains of the bay was larger than that between the strains collected in high and low tide.