Using the dredger fill sample from Nansha area,we carry out a series of tests in laboratory for the grading,phase,microstructure,element content,and specific surface area analysis.We also obtain the basic physical and mechanical indices by geotechnical experiment.Through comprehensive analysis from the views of physics to chemistry and by the macro way to micro way,we obtain the phase structure characteristics of dredger fill from Nansha area.Test results show that dredger fill is mainly of muscovite and quartz;microstructure appears as flocculation plate;the mass fraction of elements O & Si constitute the majority.The specific surface area is less for clay minerals,so it causes relatively weak minute electric field and combined water film.