We examined fluctuation about sedimentary environment and benthic biota of the Okigamisenishi point in Inner Ariake Sea. and focused on the impact of formation of oxygen-deficient water and resuspension of fine sediments with the typhoon in Summer 2006. As a result, about the relation between oxygen-deficient water and benthos, benthos with poor mobility as Annelida, Mollusca fluctuated corresponding to change of dissolved oxygen, while Arthropod escaped from the ocean space of oxygen-deficient water. About the relation between water contet of fine sediments and benthos, decrease in water content was increased the stability of the sediments, and benthic species and population increased. Dissolved oxygen and water content are an important environmental factors of the benthic habitat.
