Jiaozhou Bay is situated at the south side of the Shandong peninsula, between long. 120°5'30"-120°24'30"E and lat. 35°58'30"-36°14'20"N. It is about 29 kilometers wide and about 33 kilometers long, with a total area of about 255 square kilometers. Its water temperature at surface is rather varied, the February monthly mean is about 2℃, while that for August is about 25℃. The salinity of sea water varies monthly, the highest average monthly salinity being 31.24‰ in June and the lowest being 29.61‰ in August. The types of tides are regular semi-diurnal, with a tidal range of not over 4.7 m usually. The universal intertidal zonation by Lewis was used for Jiaozhou Bay, in which the belt from upper limit of Littorina to upper limit of barnacles is called littoral fringe, whereas that from upper limit of barnacles to upper limit of Laminaria is called eulittoral. In order to see how far the subjectively recognized zones represent an overall organism structure, we carried out a hierarchic distance analysis. The analysis was an example of a divisive shortest distance classification and information theory, in which frequency and cover data for individual species were used as the basis for both classification and amount of information. From the species pair association matrices, we constructed a hierarchical dendrogram to indicate the occurrence of some major subgroups.