The fluorine adsorbent of a magnesia based lanthanum composite was synthesized by co-precipitation method using magnesium nitrate and lanthanum nitrate as main materials. The composite powder was further molded into grains with polyvinyl alcohol (PVA) and polyvinylidene fluoride (PVDF) with a di-ameter of around 0.5cm by using extrusion molding. XRD, SEM and FTIR were used to characterize and analyze the prepared composite adsorbents. The performance of the powdered and granular composite adsorbents on the absorption of F- in aqueous solutions was tested and analyzed respectively. The results showed that the maximum adsorption of F- could reach 142.85mg/g with the powdered composite adsor-bent. The best pH for F- adsorption was found in the range of 4~10, and the adsorption equilibrium could be reached within 200min. At 25℃, the adsorption of F- with the magnesia/lanthanum composite adsor-bent was well fitted by the Langmuir isothermal adsorption model and the adsorption kinetics could be well described by the pseudo-second-order kinetic model.