Qeshm is the biggest Iranian island in the Persian Gulf which is separated from Iranian coastline by the Clarence strait. Northwestern part of island consists of Mangrove forests in form of coastal marsh and marly sediments with grooved tidal channels. Twenty seven genera and fifty four species of benthic foraminifera were determined in the sediments of this region. It is important to note that foraminifera with coiled tests are abundant in the region mangrove forest muddy and clayly beds. Further offshore, uniserial, biserial or triserial tests exists with more abundancy and diversity .On the basis of sediment logical studies northern coasts beds, particularly in the northwestern part is muddy and clayey which is appropriate for abundancy and diversity of foraminifera with hyaline tests.