Trawl survey data collected by the RV Mutiara 4 in 1979 off the north coast of Central Java (Indonesia) were used to examine the composition and distribution of species assemblages in the area. Classification (TWINSPAN) and ordination (DCA) techniques commonly used in community structure analysis were utilized during the study. The results indicate the existence of “shallow” and “deep” assemblages with a boundary at around 20 - 30 m depth (varying with the monsoon season). There is some consistency in the assemblages between the seasons.