Abstract: Modern surface sediment samples collected from the tidal flats of the Jiangsu middle-south coast were quantitatively analysed. The results show the foraminiferal taphocoenoses are mixed from the indigenous with allochthonous compositions. The features of the taphoconoses are high in diversity, strongly variable in abundance, small in test size, rich in planktonic forms and common in mechanical destruction (test abrasion and brokenness). All these features are related tidal transport processes which are the dominant hydrodynamis conditions in the study area. During the transport, deposition processes, foraminiferal tests are well sorted, mixed and destructed. Therefore, the foraminiferal taphocoenoses in the study area are the combined product of ecoloeical and taphonomic factors of the environment.