The hydraulic factors caused by the fluctuation flow and the filter mechanism of the geotextile filter of sea embankment are researched. There will be an adhesion force existing among the grains that have a diameter less than 0.6mm. Meanwhile

the soil grains are subjected to the shear stress developed by the flow because the filter and the embankment body have different seepage velocity.After the shear stress developed by the flow that make the soil grains deformed; the submit stress around the soil grains

the wave pressure etc. are analyzed. Therefore

based on the principle of balance

the retention criterion of the geotextile filter is proposed.