As a new building material,geosynthetic plays an increasingly important role in engineering construction.Aiming at the anti-seepage and anti-filtration effects of this type of material in the land reclamation project,we analyze the physical and hydraulic characteristics of the material,and introduce the role and function of the material in different construction environment combining with the cofferdam and enclosure engineers of the dredger filling project.The results show that geosynthetic can play a very excellent role of anti-seepage and filtration in dredger filling project.The shortcomings of geosynthetic should be avoided or properly protected in order to maximize its main function.