A series of environmental surveys on an intertidal flat in the inner part of Tokyo bay were conducted. The survey aims were: (1)to gain a better understanding of tidal flat environment, (2)to assess relationships between environmental parameters and the structure of benthic communities, and (3)to test prediction methods for determining the abundance of benthic communities. Wave and current climate zones were determined for the tidal flat. These zones detemined closely correlated with bottom sediment status which varied both spatially and temporally. Sediment respiration rates were determined by laboratory test and in situ observations. Benthic community zonation was also performed by grouping over suitable abundant species.